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Sunday, December 6, 2009

Change The Default Location For Installing Apps

As the size of hardrives increase, more people are using partitions to seperate and store groups of files.

XP uses the C:\Program Files directory as the default base directory into which new programs are installed. However, you can change the default installation drive and/ or directory by using a Registry hack.

Run the Registry Editor (regedit)and go to

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion

Look for the value named ProgramFilesDir. by default,this value will be C:\Program Files. Edit the value to any valid drive or folder and XP will use that new location as the default installation directory for new programs.

Booting XP Fast

Boot Winxp Fast

Follow the following steps

1. Open notepad.exe, type "del c:\windows\prefetch\ntosboot-*.* /q" (without the quotes) & save as "ntosboot.bat" in c:\
2. From the Start menu, select "Run..." & type "gpedit.msc".
3. Double click "Windows Settings" under "Computer Configuration" and double click again on "Shutdown" in the right window.
4. In the new window, click "add", "Browse", locate your "ntosboot.bat" file & click "Open".
5. Click "OK", "Apply" & "OK" once again to exit.
6. From the Start menu, select "Run..." & type "devmgmt.msc".
7. Double click on "IDE ATA/ATAPI controllers"
8. Right click on "Primary IDE Channel" and select "Properties".
9. Select the "Advanced Settings" tab then on the device or 1 that doesn't have 'device type' greyed out select 'none' instead of 'autodetect' & click "OK".
10. Right click on "Secondary IDE channel", select "Properties" and repeat step 9.
11. Reboot your computer.

.BIN & .CUE simple tutorial.

There always seems to be the question "what do I do with a .bin and .cue file" in these forums so I figured I would write a quick and simple tutorial. Please feel free to add more.

So you have downloaded two files, one with a .bin extension and one with a .cue extension. "What do I do with these?" you ask. There are a number of options.

BURN TO CD

You will need either NERO, CDRWIN or FIREBURNER to burn the file.

To burn with NERO:
Start NERO, choose FILE, choose BURN IMAGE, locate the .cue file you have and double click it. A dialog box will come up, for anything other than music make sure you choose DISC-AT-ONCE (DAO). You can also turn off the simulation burn if you so choose.
Then burn away.

To burn with CDRWin:
Start CDRWin, choose the button on the top left, choose LOAD CUESHEET, press START RECORDING.

To burn with Fireburner:
Start Fireburner, click on the button on the bottom left corner "VISUAL CUE BURNER/BINCHUNKER", press the right mouse button and choose LOAD TRACKS FROM .CUE and choose the correct .CUE file, press the right mouse button again and chooseselect "Burn/Test Burn", choose DISK AT ONCE (DAO), disable TEST BURN and MULTISESSION, press OK.

.CUE ERRORS
The most common error you will get with a .cue file is when it points to an incorrect path. This is easily fixed. Find the .bin file, copy the exact title including the .bin extension. Now find the .cue file, open the .cue file using notepad. It should look similar to this:

FILE "name of file.bin" BINARY
TRACK 01 MODE2/2352
INDEX 01 00:00:00
TRACK 02 MODE2/2352
INDEX 00 00:04:00
INDEX 01 00:06:00

Delete everything in the quotes, in this case we would
delete name of file.bin. Now place the title you copied
in between the quotes. Save the changes and close out.
Thats it, your .cue file should work now.

OTHER WAYS TO USE .BIN & .CUE FILES

VCDGear:
This program will allow you to extract MPEG streams from CD images, convert VCD files to MPEG, correct MPEG errors, and more.

Daemon Tools:
This program creates a virtual drive on your PC which will allow you to "mount" the .cue file and use whatever is in the .bin file without having to burn it to a cd.

ISOBuster:
This program will allow you to "bust" open the .bin file and extract the files within the .bin.
_________________

Best Keyboard Shotcuts

Getting used to using your keyboard exclusively and leaving your mouse behind will make you much more efficient at performing any task on any Windows system. I use the following keyboard shortcuts every day:

Windows key + R = Run menu

This is usually followed by:
cmd = Command Prompt
iexplore + "web address" = Internet Explorer
compmgmt.msc = Computer Management
dhcpmgmt.msc = DHCP Management
dnsmgmt.msc = DNS Management
services.msc = Services
eventvwr = Event Viewer
dsa.msc = Active Directory Users and Computers
dssite.msc = Active Directory Sites and Services
Windows key + E = Explorer

ALT + Tab = Switch between windows

ALT, Space, X = Maximize window

CTRL + Shift + Esc = Task Manager

Windows key + Break = System properties

Windows key + F = Search

Windows key + D = Hide/Display all windows

CTRL + C = copy

CTRL + X = cut

CTRL + V = paste

Also don't forget about the "Right-click" key next to the right Windows key on your keyboard. Using the arrows and that key can get just about anything done once you've opened up any program.


Keyboard Shortcuts

[Alt] and [Esc] Switch between running applications

[Alt] and letter Select menu item by underlined letter

[Ctrl] and [Esc] Open Program Menu

[Ctrl] and [F4] Close active document or group windows (does not work with some applications)

[Alt] and [F4] Quit active application or close current window

[Alt] and [-] Open Control menu for active document

Ctrl] Lft., Rt. arrow Move cursor forward or back one word

Ctrl] Up, Down arrow Move cursor forward or back one paragraph

[F1] Open Help for active application

Windows+M Minimize all open windows

Shift+Windows+M Undo minimize all open windows

Windows+F1 Open Windows Help

Windows+Tab Cycle through the Taskbar buttons

Windows+Break Open the System Properties dialog box



acessability shortcuts

Right SHIFT for eight seconds........ Switch FilterKeys on and off.

Left ALT +left SHIFT +PRINT SCREEN....... Switch High Contrast on and off.

Left ALT +left SHIFT +NUM LOCK....... Switch MouseKeys on and off.

SHIFT....... five times Switch StickyKeys on and off.

NUM LOCK...... for five seconds Switch ToggleKeys on and off.

explorer shortcuts

END....... Display the bottom of the active window.

HOME....... Display the top of the active window.

NUM LOCK+ASTERISK....... on numeric keypad (*) Display all subfolders under the selected folder.

NUM LOCK+PLUS SIGN....... on numeric keypad (+) Display the contents of the selected folder.

NUM LOCK+MINUS SIGN....... on numeric keypad (-) Collapse the selected folder.

LEFT ARROW...... Collapse current selection if it's expanded, or select parent folder.

RIGHT ARROW....... Display current selection if it's collapsed, or select first subfolder.




Type the following commands in your Run Box (Windows Key + R) or Start Run

devmgmt.msc = Device Manager
msinfo32 = System Information
cleanmgr = Disk Cleanup
ntbackup = Backup or Restore Wizard (Windows Backup Utility)
mmc = Microsoft Management Console
excel = Microsoft Excel (If Installed)
msaccess = Microsoft Access (If Installed)
powerpnt = Microsoft PowerPoint (If Installed)
winword = Microsoft Word (If Installed)
frontpg = Microsoft FrontPage (If Installed)
notepad = Notepad
wordpad = WordPad
calc = Calculator
msmsgs = Windows Messenger
mspaint = Microsoft Paint
wmplayer = Windows Media Player
rstrui = System Restore
netscp6 = Netscape 6.x
netscp = Netscape 7.x
netscape = Netscape 4.x
waol = America Online
control = Opens the Control Panel
control printers = Opens the Printers Dialog


internetbrowser

type in u're adress "google", then press [Right CTRL] and [Enter]
add www. and .com to word and go to it


For Windows XP:

Copy. CTRL+C
Cut. CTRL+X
Paste. CTRL+V
Undo. CTRL+Z
Delete. DELETE
Delete selected item permanently without placing the item in the Recycle Bin. SHIFT+DELETE
Copy selected item. CTRL while dragging an item
Create shortcut to selected item. CTRL+SHIFT while dragging an item
Rename selected item. F2
Move the insertion point to the beginning of the next word. CTRL+RIGHT ARROW
Move the insertion point to the beginning of the previous word. CTRL+LEFT ARROW
Move the insertion point to the beginning of the next paragraph. CTRL+DOWN ARROW
Move the insertion point to the beginning of the previous paragraph. CTRL+UP ARROW
Highlight a block of text. CTRL+SHIFT with any of the arrow keys
Select more than one item in a window or on the desktop, or select text within a document. SHIFT with any of the arrow keys
Select all. CTRL+A
Search for a file or folder. F3
View properties for the selected item. ALT+ENTER
Close the active item, or quit the active program. ALT+F4
Opens the shortcut menu for the active window. ALT+SPACEBAR
Close the active document in programs that allow you to have multiple documents open simultaneously. CTRL+F4
Switch between open items. ALT+TAB
Cycle through items in the order they were opened. ALT+ESC
Cycle through screen elements in a window or on the desktop. F6
Display the Address bar list in My Computer or Windows Explorer. F4
Display the shortcut menu for the selected item. SHIFT+F10
Display the System menu for the active window. ALT+SPACEBAR
Display the Start menu. CTRL+ESC
Display the corresponding menu. ALT+Underlined letter in a menu name
Carry out the corresponding command. Underlined letter in a command name on an open menu
Activate the menu bar in the active program. F10
Open the next menu to the right, or open a submenu. RIGHT ARROW
Open the next menu to the left, or close a submenu. LEFT ARROW
Refresh the active window. F5
View the folder one level up in My Computer or Windows Explorer. BACKSPACE
Cancel the current task. ESC
SHIFT when you insert a CD into the CD-ROM drive Prevent the CD from automatically playing.

Use these keyboard shortcuts for dialog boxes:

To Press
Move forward through tabs. CTRL+TAB
Move backward through tabs. CTRL+SHIFT+TAB
Move forward through options. TAB
Move backward through options. SHIFT+TAB
Carry out the corresponding command or select the corresponding option. ALT+Underlined letter
Carry out the command for the active option or button. ENTER
Select or clear the check box if the active option is a check box. SPACEBAR
Select a button if the active option is a group of option buttons. Arrow keys
Display Help. F1
Display the items in the active list. F4
Open a folder one level up if a folder is selected in the Save As or Open dialog box. BACKSPACE

If you have a Microsoft Natural Keyboard, or any other compatible keyboard that includes the Windows logo key and the Application key , you can use these keyboard shortcuts:


Display or hide the Start menu. WIN Key
Display the System Properties dialog box. WIN Key+BREAK
Show the desktop. WIN Key+D
Minimize all windows. WIN Key+M
Restores minimized windows. WIN Key+Shift+M
Open My Computer. WIN Key+E
Search for a file or folder. WIN Key+F
Search for computers. CTRL+WIN Key+F
Display Windows Help. WIN Key+F1
Lock your computer if you are connected to a network domain, or switch users if you are not connected to a network domain. WIN Key+ L
Open the Run dialog box. WIN Key+R
Open Utility Manager. WIN Key+U

accessibility keyboard shortcuts:

Switch FilterKeys on and off. Right SHIFT for eight seconds
Switch High Contrast on and off. Left ALT+left SHIFT+PRINT SCREEN
Switch MouseKeys on and off. Left ALT +left SHIFT +NUM LOCK
Switch StickyKeys on and off. SHIFT five times
Switch ToggleKeys on and off. NUM LOCK for five seconds
Open Utility Manager. WIN Key+U

shortcuts you can use with Windows Explorer:


Display the bottom of the active window. END
Display the top of the active window. HOME
Display all subfolders under the selected folder. NUM LOCK+ASTERISK on numeric keypad (*)
Display the contents of the selected folder. NUM LOCK+PLUS SIGN on numeric keypad (+)
Collapse the selected folder. NUM LOCK+MINUS SIGN on numeric keypad (-)
Collapse current selection if it's expanded, or select parent folder. LEFT ARROW
Display current selection if it's collapsed, or select first subfolder. RIGHT ARROW

Error Code Manual

After repeated requests for beep codes i have decided to post them here maybe they could be pinned

Standard Original IBM POST Error Codes
Code Description

1 short beep System is OK
2 short beeps POST Error - error code shown on screen No beep Power supply or system board problem Continuous beep Power supply, system board, or keyboard problem Repeating short beeps Power supply or system board problem
1 long, 1 short beep System board problem
1 long, 2 short beeps Display adapter problem (MDA, CGA)
1 long, 3 short beeps Display adapter problem (EGA)
3 long beeps 3270 keyboard card
IBM POST Diagnostic Code Descriptions
Code Description
100 - 199 System Board
200 - 299 Memory
300 - 399 Keyboard
400 - 499 Monochrome Display
500 - 599 Colour/Graphics Display
600 - 699 Floppy-disk drive and/or Adapter
700 - 799 Math Coprocessor
900 - 999 Parallel Printer Port
1000 - 1099 Alternate Printer Adapter
1100 - 1299 Asynchronous Communication Device, Adapter, or Port
1300 - 1399 Game Port
1400 - 1499 Colour/Graphics Printer
1500 - 1599 Synchronous Communication Device, Adapter, or Port
1700 - 1799 Hard Drive and/or Adapter
1800 - 1899 Expansion Unit (XT)
2000 - 2199 Bisynchronous Communication Adapter
2400 - 2599 EGA system-board Video (MCA)
3000 - 3199 LAN Adapter
4800 - 4999 Internal Modem
7000 - 7099 Phoenix BIOS Chips
7300 - 7399 3.5" Disk Drive
8900 - 8999 MIDI Adapter
11200 - 11299 SCSI Adapter
21000 - 21099 SCSI Fixed Disk and Controller
21500 - 21599 SCSI CD-ROM System

AMI BIOS Beep Codes
Code Description

1 Short Beep System OK
2 Short Beeps Parity error in the first 64 KB of memory
3 Short Beeps Memory failure in the first 64 KB
4 Short Beeps Memory failure in the first 64 KB Operational of memory
or Timer 1 on the motherboard is not functioning
5 Short Beeps The CPU on the motherboard generated an error
6 Short Beeps The keyboard controller may be bad. The BIOS cannot switch to protected mode
7 Short Beeps The CPU generated an exception interrupt
8 Short Beeps The system video adapter is either missing, or its memory is faulty
9 Short Beeps The ROM checksum value does not match the value encoded in the BIOS
10 Short Beeps The shutdown register for CMOS RAM failed
11 Short Beeps The external cache is faulty
1 Long, 3 Short Beeps Memory Problems
1 Long, 8 Short Beeps Video Card Problems

Phoenix BIOS Beep Codes
Note - Phoenix BIOS emits three sets of beeps, separated by a brief pause.

Code Description
1-1-3 CMOS read/write failure
1-1-4 ROM BIOS checksum error
1-2-1 Programmable interval timer failure
1-2-2 DMA initialisation failure
1-2-3 DMA page register read/write failure
1-3-1 RAM refresh verification failure
1-3-3 First 64k RAM chip or data line failure
1-3-4 First 64k RAM odd/even logic failure
1-4-1 Address line failure first 64k RAM
1-4-2 Parity failure first 64k RAM
2-_-_ Faulty Memory
3-1-_ Faulty Motherboard
3-2-4 Keyboard controller Test failure
3-3-4 Screen initialisation failure
3-4-1 Screen retrace test failure
3-4-2 Search for video ROM in progress
4-2-1 Timer tick interrupt in progress or failure
4-2-2 Shutdown test in progress or failure
4-2-3 Gate A20 failure
4-2-4 Unexpected interrupt in protected mode
4-3-1 RAM test in progress or failure>ffffh
4-3-2 Faulty Motherboard
4-3-3 Interval timer channel 2 test or failure
4-3-4 Time of Day clock test failure
4-4-1 Serial port test or failure
4-4-2 Parallel port test or failure
4-4-3 Math coprocessor test or failure
Low 1-1-2 System Board select failure
Low 1-1-3 Extended CMOS RAM failure

Beep Code Manual !!!!

Beep Code Manual, Better Than Gold Techies, American Megatrends Int. & Phoenix


BIOS Beep Codes

When a computer is first turned on, or rebooted, its BIOS performs a power-on self test (POST) to test the system's hardware, checking to make sure that all of the system's hardware components are working properly. Under normal circumstances, the POST will display an error message; however, if the BIOS detects an error before it can access the video card, or if there is a problem with the video card, it will produce a series of beeps, and the pattern of the beeps indicates what kind of problem the BIOS has detected.
Because there are many brands of BIOS, there are no standard beep codes for every BIOS.

The two most-used brands are AMI (American Megatrends International) and Phoenix.

Below are listed the beep codes for AMI systems, and here are the beep codes for Phoenix systems.


AMI Beep Codes

Beep Code Meaning
1 beep DRAM refresh failure. There is a problem in the system memory or the motherboard.
2 beeps Memory parity error. The parity circuit is not working properly.
3 beeps Base 64K RAM failure. There is a problem with the first 64K of system memory.
4 beeps System timer not operational. There is problem with the timer(s) that control functions on the motherboard.
5 beeps Processor failure. The system CPU has failed.
6 beeps Gate A20/keyboard controller failure. The keyboard IC controller has failed, preventing gate A20 from switching the processor to protect mode.
7 beeps Virtual mode exception error.
8 beeps Video memory error. The BIOS cannot write to the frame buffer memory on the video card.
9 beeps ROM checksum error. The BIOS ROM chip on the motherboard is likely faulty.
10 beeps CMOS checksum error. Something on the motherboard is causing an error when trying to interact with the CMOS.
11 beeps Bad cache memory. An error in the level 2 cache memory.
1 long beep, 2 short Failure in the video system.
1 long beep, 3 short A failure has been detected in memory above 64K.
1 long beep, 8 short Display test failure.
Continuous beeping A problem with the memory or video.
BIOS Beep Codes


Phoenix Beep Codes

Phoenix uses sequences of beeps to indicate problems. The "-" between each number below indicates a pause between each beep sequence. For example, 1-2-3 indicates one beep, followed by a pause and two beeps, followed by a pause and three beeps. Phoenix version before 4.x use 3-beep codes, while Phoenix versions starting with 4.x use 4-beep codes. Click here for AMI BIOS beep codes.
4-Beep Codes
Beep Code Meaning
1-1-1-3 Faulty CPU/motherboard. Verify real mode.
1-1-2-1 Faulty CPU/motherboard.
1-1-2-3 Faulty motherboard or one of its components.
1-1-3-1 Faulty motherboard or one of its components. Initialize chipset registers with initial POST values.
1-1-3-2 Faulty motherboard or one of its components.
1-1-3-3 Faulty motherboard or one of its components. Initialize CPU registers.
1-1-3-2
1-1-3-3
1-1-3-4 Failure in the first 64K of memory.
1-1-4-1 Level 2 cache error.
1-1-4-3 I/O port error.
1-2-1-1 Power management error.
1-2-1-2
1-2-1-3 Faulty motherboard or one of its components.
1-2-2-1 Keyboard controller failure.
1-2-2-3 BIOS ROM error.
1-2-3-1 System timer error.
1-2-3-3 DMA error.
1-2-4-1 IRQ controller error.
1-3-1-1 DRAM refresh error.
1-3-1-3 A20 gate failure.
1-3-2-1 Faulty motherboard or one of its components.
1-3-3-1 Extended memory error.
1-3-3-3
1-3-4-1
1-3-4-3 Error in first 1MB of system memory.
1-4-1-3
1-4-2-4 CPU error.
1-4-3-1
2-1-4-1 BIOS ROM shadow error.
1-4-3-2
1-4-3-3 Level 2 cache error.
1-4-4-1
1-4-4-2
2-1-1-1 Faulty motherboard or one of its components.
2-1-1-3
2-1-2-1 IRQ failure.
2-1-2-3 BIOS ROM error.
2-1-2-4
2-1-3-2 I/O port failure.
2-1-3-1
2-1-3-3 Video system failure.
2-1-1-3
2-1-2-1 IRQ failure.
2-1-2-3 BIOS ROM error.
2-1-2-4 I/O port failure.
2-1-4-3
2-2-1-1 Video card failure.
2-2-1-3
2-2-2-1
2-2-2-3 Keyboard controller failure.
2-2-3-1 IRQ error.
2-2-4-1 Error in first 1MB of system memory.
2-3-1-1
2-3-3-3 Extended memory failure.
2-3-2-1 Faulty motherboard or one of its components.
2-3-2-3
2-3-3-1 Level 2 cache error.
2-3-4-1
2-3-4-3 Motherboard or video card failure.
2-3-4-1
2-3-4-3
2-4-1-1 Motherboard or video card failure.
2-4-1-3 Faulty motherboard or one of its components.
2-4-2-1 RTC error.
2-4-2-3 Keyboard controller error.
2-4-4-1 IRQ error.
3-1-1-1
3-1-1-3
3-1-2-1
3-1-2-3 I/O port error.
3-1-3-1
3-1-3-3 Faulty motherboard or one of its components.
3-1-4-1
3-2-1-1
3-2-1-2 Floppy drive or hard drive failure.
3-2-1-3 Faulty motherboard or one of its components.
3-2-2-1 Keyboard controller error.
3-2-2-3
3-2-3-1
3-2-4-1 Faulty motherboard or one of its components.
3-2-4-3 IRQ error.
3-3-1-1 RTC error.
3-3-1-3 Key lock error.
3-3-3-3 Faulty motherboard or one of its components.
3-3-3-3
3-3-4-1
3-3-4-3
3-4-1-1
3-4-1-3
3-4-2-1
3-4-2-3
3-4-3-1
3-4-4-1
3-4-4-4 Faulty motherboard or one of its components.
4-1-1-1 Floppy drive or hard drive failure.
4-2-1-1
4-2-1-3
4-2-2-1 IRQ failure.
4-2-2-3
4-2-3-1
4-2-3-3
4-2-4-1 Faulty motherboard or one of its components.
4-2-4-3 Keyboard controller error.
4-3-1-3
4-3-1-4
4-3-2-1
4-3-2-2
4-3-3-1
4-3-4-1
4-3-4-3 Faulty motherboard or one of its components.
4-3-3-2
4-3-3-4 IRQ failure.
4-3-3-3
4-3-4-2 Floppy drive or hard drive failure.
3-Beep Codes
Beep Code Meaning
1-1-2 Faulty CPU/motherboard.
1-1-3 Faulty motherboard/CMOS read-write failure.
1-1-4 Faulty BIOS/BIOS ROM checksum error.
1-2-1 System timer not operational. There is a problem with the timer(s) that control functions on the motherboard.
1-2-2
1-2-3 Faulty motherboard/DMA failure.
1-3-1 Memory refresh failure.
1-3-2
1-3-3
1-3-4 Failure in the first 64K of memory.
1-4-1 Address line failure.
1-4-2 Parity RAM failure.
1-4-3 Timer failure.
1-4-4 NMI port failure.
2-_-_ Any combination of beeps after 2 indicates a failure in the first 64K of memory.
3-1-1 Master DMA failure.
3-1-2 Slave DMA failure.
3-1-3
3-1-4 Interrupt controller failure.
3-2-4 Keyboard controller failure.
3-3-1
3-3-2 CMOS error.
3-3-4 Video card failure.
3-4-1 Video card failure.
4-2-1 Timer failure.
4-2-2 CMOS shutdown failure.
4-2-3 Gate A20 failure.
4-2-4 Unexpected interrupt in protected mode.
4-3-1 RAM test failure.
4-3-3 Timer failure.
4-3-4 Time of day clock failure.
4-4-1 Serial port failure.
4-4-2 Parallel port failure.
4-4-3 Math coprocessor.

What is BANDWIDTH?????????????

This is well written explanation about bandwidth, very useful info.



BandWidth Explained

Most hosting companies offer a variety of bandwidth options in their plans. So exactly what is bandwidth as it relates to web hosting? Put simply, bandwidth is the amount of traffic that is allowed to occur between your web site and the rest of the internet. The amount of bandwidth a hosting company can provide is determined by their network connections, both internal to their data center and external to the public internet.


Network Connectivity

The internet, in the most simplest of terms, is a group of millions of computers connected by networks. These connections within the internet can be large or small depending upon the cabling and equipment that is used at a particular internet location. It is the size of each network connection that determines how much bandwidth is available. For example, if you use a DSL connection to connect to the internet, you have 1.54 Mega bits (Mb) of bandwidth. Bandwidth therefore is measured in bits (a single 0 or 1). Bits are grouped in bytes which form words, text, and other information that is transferred between your computer and the internet.

If you have a DSL connection to the internet, you have dedicated bandwidth between your computer and your internet provider. But your internet provider may have thousands of DSL connections to their location. All of these connection aggregate at your internet provider who then has their own dedicated connection to the internet (or multiple connections) which is much larger than your single connection. They must have enough bandwidth to serve your computing needs as well as all of their other customers. So while you have a 1.54Mb connection to your internet provider, your internet provider may have a 255Mb connection to the internet so it can accommodate your needs and up to 166 other users (255/1.54).


Traffic

A very simple analogy to use to understand bandwidth and traffic is to think of highways and cars. Bandwidth is the number of lanes on the highway and traffic is the number of cars on the highway. If you are the only car on a highway, you can travel very quickly. If you are stuck in the middle of rush hour, you may travel very slowly since all of the lanes are being used up.

Traffic is simply the number of bits that are transferred on network connections. It is easiest to understand traffic using examples. One Gigabyte is 2 to the 30th power (1,073,741,824) bytes. One gigabyte is equal to 1,024 megabytes. To put this in perspective, it takes one byte to store one character. Imagine 100 file cabinets in a building, each of these cabinets holds 1000 folders. Each folder has 100 papers. Each paper contains 100 characters - A GB is all the characters in the building. An MP3 song is about 4MB, the same song in wav format is about 40MB, a full length movie can be 800MB to 1000MB (1000MB = 1GB).

If you were to transfer this MP3 song from a web site to your computer, you would create 4MB of traffic between the web site you are downloading from and your computer. Depending upon the network connection between the web site and the internet, the transfer may occur very quickly, or it could take time if other people are also downloading files at the same time. If, for example, the web site you download from has a 10MB connection to the internet, and you are the only person accessing that web site to download your MP3, your 4MB file will be the only traffic on that web site. However, if three people are all downloading that same MP at the same time, 12MB (3 x 4MB) of traffic has been created. Because in this example, the host only has 10MB of bandwidth, someone will have to wait. The network equipment at the hosting company will cycle through each person downloading the file and transfer a small portion at a time so each person's file transfer can take place, but the transfer for everyone downloading the file will be slower. If 100 people all came to the site and downloaded the MP3 at the same time, the transfers would be extremely slow. If the host wanted to decrease the time it took to download files simultaneously, it could increase the bandwidth of their internet connection (at a cost due to upgrading equipment).


Hosting Bandwidth

In the example above, we discussed traffic in terms of downloading an MP3 file. However, each time you visit a web site, you are creating traffic, because in order to view that web page on your computer, the web page is first downloaded to your computer (between the web site and you) which is then displayed using your browser software (Internet Explorer, Netscape, etc.) . The page itself is simply a file that creates traffic just like the MP3 file in the example above (however, a web page is usually much smaller than a music file).

A web page may be very small or large depending upon the amount of text and the number and quality of images integrated within the web page. For example, the home page for CNN.com is about 200KB (200 Kilobytes = 200,000 bytes = 1,600,000 bits). This is typically large for a web page. In comparison, Yahoo's home page is about 70KB.


How Much Bandwidth Is Enough?

It depends (don't you hate that answer). But in truth, it does. Since bandwidth is a significant determinant of hosting plan prices, you should take time to determine just how much is right for you. Almost all hosting plans have bandwidth requirements measured in months, so you need to estimate the amount of bandwidth that will be required by your site on a monthly basis

If you do not intend to provide file download capability from your site, the formula for calculating bandwidth is fairly straightforward:

Average Daily Visitors x Average Page Views x Average Page Size x 31 x Fudge Factor

If you intend to allow people to download files from your site, your bandwidth calculation should be:

[(Average Daily Visitors x Average Page Views x Average Page Size) +
(Average Daily File Downloads x Average File Size)] x 31 x Fudge Factor

Let us examine each item in the formula:

Average Daily Visitors - The number of people you expect to visit your site, on average, each day. Depending upon how you market your site, this number could be from 1 to 1,000,000.

Average Page Views - On average, the number of web pages you expect a person to view. If you have 50 web pages in your web site, an average person may only view 5 of those pages each time they visit.

Average Page Size - The average size of your web pages, in Kilobytes (KB). If you have already designed your site, you can calculate this directly.

Average Daily File Downloads - The number of downloads you expect to occur on your site. This is a function of the numbers of visitors and how many times a visitor downloads a file, on average, each day.

Average File Size - Average file size of files that are downloadable from your site. Similar to your web pages, if you already know which files can be downloaded, you can calculate this directly.

Fudge Factor - A number greater than 1. Using 1.5 would be safe, which assumes that your estimate is off by 50%. However, if you were very unsure, you could use 2 or 3 to ensure that your bandwidth requirements are more than met.

Usually, hosting plans offer bandwidth in terms of Gigabytes (GB) per month. This is why our formula takes daily averages and multiplies them by 31.


Summary

Most personal or small business sites will not need more than 1GB of bandwidth per month. If you have a web site that is composed of static web pages and you expect little traffic to your site on a daily basis, go with a low bandwidth plan. If you go over the amount of bandwidth allocated in your plan, your hosting company could charge you over usage fees, so if you think the traffic to your site will be significant, you may want to go through the calculations above to estimate the amount of bandwidth required in a hosting plan.

Cool Regedit Trick

ok m8s,
any of you that do websites and like to open .html and similar files in notepad to edit scrpits, this is THE coolest windows registry edit ever
you can download the zip file with the .reg in it (run it and it automatically adds itself to your registry) or do it manually
CODE
http://www.geocities.com/ichbindeingott5/winXP-Notepad.zip


Manually: regedit and navigate to
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\*\Shell
add the key "notepad"
it's default value should be "Open with Notepad"
now, under "notepad", add the key "Command"
it's default value should be (with the quotes) "C:\Windows\System32\Notepad.exe" "%1"

ok, exit regedit and go right click on ANY file...
your new option: Open with Notepad

HOW IS THAT?!?!?!?
I FOUND THIS ONE ON MY OWN!!!!!!

i know this one works on XP and 2000, you can PROBABLY enter it manually on windows 9x, but i have not tested that


okay okay, i know maybe not everyone cares...but this was fun for me because i love tweaking my computer AND it makes some web design stuff eaiser for me :D

Auto End Tasks to Enable a Proper Shutdown, Win XP Tweak

Auto End Tasks to Enable a Proper Shutdown

This reg file automatically ends tasks and timeouts that prevent programs from shutting down and clears the Paging File on Exit.

1. Copy the following (everything in the box) into notepad.


QUOTE
Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]
"ClearPageFileAtShutdown"=dword:00000001

[HKEY_USERS\.DEFAULT\Control Panel\Desktop]
"AutoEndTasks"="1"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control]
"WaitToKillServiceTimeout"="1000"


2. Save the file as shutdown.reg
3. Double click the file to import into your registry.

NOTE: If your anti-virus software warns you of a "malicious" script, this is normal if you have "Script Safe" or similar technology enabled.

All About Movie Tags (what is a Dvdrip, Cam Etc)

Original Sources

CAM -
A cam is a theater rip usually done with a digital video camera. A mini tripod is sometimes used, but a lot of the time this wont be possible, so the camera make shake. Also seating placement isn't always idle, and it might be filmed from an angle. If cropped properly, this is hard to tell unless there's text on the screen, but a lot of times these are left with triangular borders on the top and bottom of the screen. Sound is taken from the onboard microphone of the camera, and especially in comedies, laughter can often be heard during the film. Due to these factors picture and sound quality are usually quite poor, but sometimes we're lucky, and the theater will be fairly empty and a fairly clear signal will be heard.



TELESYNC (TS) - A telesync is the same spec as a CAM except it uses an external audio source (most likely an audio jack in the chair for hard of hearing people). A direct audio source does not ensure a good quality audio source, as a lot of background noise can interfere. A lot of the times a telesync is filmed in an empty cinema or from the projection booth with a professional camera, giving a better picture quality. Quality ranges drastically, check the sample before downloading the full release. A high percentage of Telesyncs are CAMs that have been mislabeled.



TELECINE (TC) -
A telecine machine copies the film digitally from the reels. Sound and picture should be very good, but due to the equipment involved and cost telecines are fairly uncommon. Generally the film will be in correct aspect ratio, although 4:3 telecines have existed. A great example is the JURASSIC PARK 3 TC done last year. TC should not be confused with TimeCode , which is a visible counter on screen throughout the film.



SCREENER (SCR) -
A pre VHS tape, sent to rental stores, and various other places for promotional use. A screener is supplied on a VHS tape, and is usually in a 4:3 (full screen) a/r, although letterboxed screeners are sometimes found. The main draw back is a "ticker" (a message that scrolls past at the bottom of the screen, with the copyright and anti-copy telephone number). Also, if the tape contains any serial numbers, or any other markings that could lead to the source of the tape, these will have to be blocked, usually with a black mark over the section. This is sometimes only for a few seconds, but unfortunately on some copies this will last for the entire film, and some can be quite big. Depending on the equipment used, screener quality can range from excellent if done from a MASTER copy, to very poor if done on an old VHS recorder thru poor capture equipment on a copied tape. Most screeners are transferred to VCD, but a few attempts at SVCD have occurred, some looking better than others.



DVD-SCREENER (DVDscr) -Same premise as a screener, but transferred off a DVD. Usually letterbox , but without the extras that a DVD retail would contain. The ticker is not usually in the black bars, and will disrupt the viewing. If the ripper has any skill, a DVDscr should be very good. Usually transferred to SVCD or DivX/XviD.



DVDRip - A copy of the final released DVD. If possible this is released PRE retail (for example, Star Wars episode 2) again, should be excellent quality. DVDrips are released in SVCD and DivX/XviD.



VHSRip -Transferred off a retail VHS, mainly skating/sports videos.



TVRip -TV episode that is either from Network (capped using digital cable/satellite boxes are preferable) or PRE-AIR from satellite feeds sending the program around to networks a few days earlier (do not contain "dogs" but sometimes have flickers etc) Some programs such as WWF Raw Is War contain extra parts, and the "dark matches" and camera/commentary tests are included on the rips. PDTV is capped from a digital TV PCI card, generally giving the best results, and groups tend to release in SVCD for these. VCD/SVCD/DivX/XviD rips are all supported by the TV scene.



WORKPRINT (WP) -A workprint is a copy of the film that has not been finished. It can be missing scenes, music, and quality can range from excellent to very poor. Some WPs are very different from the final print (Men In Black is missing all the aliens, and has actors in their places) and others can contain extra scenes (Jay and Silent Bob) . WPs can be nice additions to the collection once a good quality final has been obtained.



DivX Re-Enc -A DivX re-enc is a film that has been taken from its original VCD source, and re-encoded into a small DivX file. Most commonly found on file sharers, these are usually labeled something like Film.Name.Group(1of2) etc. Common groups are SMR and TND. These aren't really worth downloading, unless you're that unsure about a film u only want a 200mb copy of it. Generally avoid.



Watermarks -
A lot of films come from Asian Silvers/PDVD (see below) and these are tagged by the people responsible. Usually with a letter/initials or a little logo, generally in one of the corners. Most famous are the "Z" "A" and "Globe" watermarks.



Asian Silvers / PDVD -
These are films put out by eastern bootleggers, and these are usually bought by some groups to put out as their own. Silvers are very cheap and easily available in a lot of countries, and its easy to put out a release, which is why there are so many in the scene at the moment, mainly from smaller groups who don't last more than a few releases. PDVDs are the same thing pressed onto a DVD. They have removable subtitles, and the quality is usually better than the silvers. These are ripped like a normal DVD, but usually released as VCD.






Formats

VCD -
VCD is an mpeg1 based format, with a constant bitrate of 1150kbit at a resolution of 352x240 (NTCS). VCDs are generally used for lower quality transfers (CAM/TS/TC/Screener(VHS)/TVrip(analogue) in order to make smaller file sizes, and fit as much on a single disc as possible. Both VCDs and SVCDs are timed in minutes, rather than MB, so when looking at an mpeg, it may appear larger than the disc capacity, and in reality u can fit 74min on a CDR74.



SVCD -
SVCD is an mpeg2 based (same as DVD) which allows variable bit-rates of up to 2500kbits at a resolution of 480x480 (NTSC) which is then decompressed into a 4:3 aspect ratio when played back. Due to the variable bit-rate, the length you can fit on a single CDR is not fixed, but generally between 35-60 Mins are the most common. To get a better SVCD encode using variable bit-rates, it is important to use multiple "passes". this takes a lot longer, but the results are far clearer.



XVCD/XSVCD -
These are basically VCD/SVCD that don't obey the "rules". They are both capable of much higher resolutions and bit-rates, but it all depends on the player to whether the disc can be played. X(S)VCD are total non-standards, and are usually for home-ripping by people who don't intend to release them.



KVCD Thanks for lardo4life for the info
KVCD is a modification to the standard MPEG-1 and MPEG-2 GOP structure and Quantization Matrix. It enables you to create over 120 minutes of near DVD quality video, depending on your material, on a single 80 minute CD-R/CD-RW. We have published these specifications as KVCDx3, our official resolution, which produce 528x480 (NTSC) and 528x576 (PAL) MPEG-1 variable bit rate video, from 64Kbps to 3,000Kbps. Using a resolution of 352x240 (NTSC) or 352x288 (PAL), it's possible to encode video up to ~360 minutes of near VCD quality on a single 80 minute CD-R. The mpeg files created will play back in most modern standalone DVD players. You must burn the KVCD MPEG files as non-standard VCD or non-standard SVCD (depends on your player) with Nero or VCDEasy.



DivX / XviD -
DivX is a format designed for multimedia platforms. It uses two codecs, one low motion, one high motion. most older films were encoded in low motion only, and they have problems with high motion too. A method known as SBC (Smart Bit-rate Control) was developed which switches codecs at the encoding stage, making a much better print. The format is Ana orphic and the bit-rate/resolution are interchangeable. Due to the higher processing power required, and the different codecs for playback, its unlikely we'll see a DVD player capable of play DivX for quite a while, if at all. There have been players in development which are supposedly capable, but nothing has ever arisen. The majority of PROPER DivX rips (not Re-Encs) are taken from DVDs, and generally up to 2hours in good quality is possible per disc. Various codecs exist, most popular being the original Divx3.11a and the new XviD codecs.



CVD -
CVD is a combination of VCD and SVCD formats, and is generally supported by a majority of DVD players. It supports MPEG2 bit-rates of SVCD, but uses a resolution of 352x480(ntsc) as the horizontal resolution is generally less important. Currently no groups release in CVD.



DVD-R -
Is the recordable DVD solution that seems to be the most popular (out of DVD-RAM, DVD-R and DVD+R). it holds 4.7gb of data per side, and double sided discs are available, so discs can hold nearly 10gb in some circumstances. SVCD mpeg2 images must be converted before they can be burnt to DVD-R and played successfully. DVD>DVDR copies are possible, but sometimes extras/languages have to be removed to stick within the available 4.7gb.



MiniDVD -
MiniDVD/cDVD is the same format as DVD but on a standard CDR/CDRW. Because of the high resolution/bit-rates, its only possible to fit about 18-21 mins of footage per disc, and the format is only compatible with a few players.






Misc Info

Regional Coding -
This was designed to stop people buying American DVDs and watching them earlier in other countries, or for older films where world distribution is handled by different companies. A lot of players can either be hacked with a chip, or via a remote to disable this.



RCE -
RCE (Regional Coding Enhancement) was designed to overcome "Multiregion" players, but it had a lot of faults and was overcome. Very few titles are RCE encoded now, and it was very unpopular.



Macrovision -
Macrovision is the copy protection employed on most commercial DVDs. Its a system that will display lines and darken the images of copies that are made by sending the VHS signals it can't understand. Certain DVD players (for example the Dansai 852 from Tescos) have a secret menu where you can disable the macrovision, or a "video stabaliser" costs about 30UKP from Maplin (www.maplin.co.uk)



NTSC/PAL -
NTSC and PAL are the two main standards used across the world. NTSC has a higher frame rate than pal (29fps compared to 25fps) but PAL has an increased resolution, and gives off a generally sharper picture. Playing NTSC discs on PAL systems seems a lot easier than vice-versa, which is good news for the Brits An RGB enabled scart lead will play an NTSC picture in full colour on most modern tv sets, but to record this to a VHS tape, you will need to convert it to PAL50 (not PAL60 as the majority of DVD players do.) This is either achieved by an expensive converter box (in the regions of £200+) an onboard converter (such as the Dansai 852 / certain Daewoos / Samsung 709 ) or using a World Standards VCR which can record in any format.



News Sites -
There are generally 2 news sites for film release for p2p and they are:

nforce - VCD Help
Code:
http://www.vcdhelp.com/

Code:
http://www.nforce.nl.




About Release Files

RARset -
The movies are all supplied in RAR form, whether its v2 (rar>.rxx) or v3 (part01.rar > partxx.rar) form.



BIN/CUE -
VCD and SVCD films will extract to give a BIN/CUE. Load the .CUE into notepad and make sure the first line contains only a filename, and no path information. Then load the cue into Nero/CDRWin etc and this will burn the VCD/SVCD correctly. TV rips are released as MPEG. DivX files are just the plain DivX - .AVI



NFO -
An NFO file is supplied with each movie to promote the group, and give general iNFOrmation about the release, such as format, source, size, and any notes that may be of use. They are also used to recruit members and acquire hardware for the group.

SFV -
Also supplied for each disc is an SFV file. These are mainly used on site level to check each file has been uploaded correctly, but are also handy for people downloading to check they have all the files, and the CRC is correct. A program such as pdSFV or hkSFV is required to use these files.






Usenet Information

Access -
To get onto newsgroups, you will need a news server. Most ISPs supply one, but this is usually of poor retention (the amount of time the files are on server for) and poor completition (the amount of files that make it there). For the best service, a premium news server should be paid for, and these will often have bandwidth restrictions in place.



Software -
You will need a newsreader to access the files in the binary newsgroups. There are many different readers, and its usually down to personal opinion which is best. Xnews / Forte Agent / BNR 1 / BNR 2 are amongst the popular choices. Outlook has the ability to read newsgroups, but its recommended to not use that.



Format -
Usenet posts are often the same as those listed on VCDQUALiTY (i.e., untouched group releases) but you have to check the filenames and the description to make sure you get what you think you are getting. Generally releases should come down in .RAR sets. Posts will usually take more than one day to be uploaded, and can be spread out as far as a week.



PAR files -
As well as the .rxx files, you will also see files listed as .pxx/.par . These are PARITY files. Parity files are common in usenet posts, as a lot of times, there will be at least one or two damaged files on some servers. A parity file can be used to replace ANY ONE file that is missing from the rar set. The more PAR files you have, the more files you can replace. You will need a program called SMARTPAR for this.






Scene Tags

PROPER -
Due to scene rules, whoever releases the first Telesync has won that race (for example). But if the quality of that release is fairly poor, if another group has another telesync (or the same source in higher quality) then the tag PROPER is added to the folder to avoid being duped. PROPER is the most subjective tag in the scene, and a lot of people will generally argue whether the PROPER is better than the original release. A lot of groups release PROPERS just out of desperation due to losing the race. A reason for the PROPER should always be included in the NFO.



SUBBED -
In the case of a VCD, if a release is subbed, it usually means it has hard encoded subtitles burnt throughout the movie. These are generally in malaysian/chinese/thai etc, and sometimes there are two different languages, which can take up quite a large amount of the screen. SVCD supports switch able subtitles, so some DVDRips are released with switch able subs. This will be mentioned in the NFO file if included.



UNSUBBED -
When a film has had a subbed release in the past, an Unsubbed release may be released

LIMITED -
A limited movie means it has had a limited theater run, generally opening in less than 250 theaters, generally smaller films (such as art house films) are released as limited.



INTERNAL -
An internal release is done for several reasons. Classic DVD groups do a lot of .INTERNAL. releases, as they wont be dupe'd on it. Also lower quality theater rips are done INTERNAL so not to lower the reputation of the group, or due to the amount of rips done already. An INTERNAL release is available as normal on the groups affiliate sites, but they can't be traded to other sites without request from the site ops. Some INTERNAL releases still trickle down to IRC/Newsgroups, it usually depends on the title and the popularity. Earlier in the year people referred to Centropy going "internal". This meant the group were only releasing the movies to their members and site ops. This is in a different context to the usual definition.



STV -
Straight To Video. Was never released in theaters, and therefore a lot of sites do not allow these.



OTHER TAGS -

*WS* for widescreen (letterbox)
*FS* for Fullscreen.



RECODE -
A recode is a previously released version, usually filtered through TMPGenc to remove subtitles, fix color etc. Whilst they can look better, its not looked upon highly as groups are expected to obtain their own sources.



REPACK -
If a group releases a bad rip, they will release a Repack which will fix the problems.



NUKED -
A film can be nuked for various reasons. Individual sites will nuke for breaking their rules (such as "No Telesyncs") but if the film has something extremely wrong with it (no soundtrack for 20mins, CD2 is incorrect film/game etc) then a global nuke will occur, and people trading it across sites will lose their credits. Nuked films can still reach other sources such as p2p/usenet, but its a good idea to check why it was nuked first in case. If a group realise there is something wrong, they can request a nuke.

NUKE REASONS :: this is a list of common reasons a film can be nuked for (generally DVDRip)

** BAD A/R ** :: bad aspect ratio, ie people appear too fat/thin
** BAD IVTC ** :: bad inverse telecine. process of converting framerates was incorrect.
** INTERLACED ** :: black lines on movement as the field order is incorrect.



DUPE -
Dupe is quite simply, if something exists already, then theres no reason for it to exist again without proper reason.

Advanced Shellcoding Techniques

Introduction

This paper assumes a working knowledge of basic shellcoding techniques, and x86 assembly, I will not rehash these in this paper.  I hope to teach you some of the lesser known shellcoding techniques that I have picked up, which will allow you to write smaller and better shellcodes.  I do not claim to have invented any of these techniques, except for the one that uses the div instruction.



The multiplicity of mul

This technique was originally developed by Sorbo of darkircop.net.  The mul instruction may, on the surface, seem mundane, and it's purpose obvious.  However, when faced with the difficult challenge of shrinking your shellcode, it proves to be quite useful.  First some background information on the mul instruction itself.

mul performs an unsigned multiply of two integers.  It takes only one operand, the other is implicitly specified by the %eax register.  So, a  common mul instruction might look something like this:

movl $0x0a,%eax
mul $0x0a

This would multiply the value stored in %eax by the operand of mul, which in this case would be 10*10.  The result is then implicitly stored in EDX:EAX.  The result is stored over a span of two registers because it has the potential to be considerably larger than the previous value, possibly exceeding the capacity of a single register(this is also how floating points are stored in some cases, as an interesting sidenote).

So, now comes the ever-important question.  How can we use these attributes to our advantage when writing shellcode?  Well, let's think for a second, the instruction takes only one operand, therefore, since it is a very common instruction, it will generate only two bytes in our final shellcode.  It multiplies whatever is passed to it by the value stored in %eax, and stores the value in both %edx and %eax, completely overwriting the contents of both registers, regardless of whether it is necessary to do so, in order to store the result of the multiplication.  Let's put on our mathematician hats for a second, and consider this, what is the only possible result of a multiplication by 0?  The answer, as you may have guessed, is 0.  I think it's about time for some example code, so here it is:

xorl %ecx,%ecx
mul %ecx

What is this shellcode doing?  Well, it 0's out the %ecx register using the xor instruction, so we now know that %ecx is 0.  Then it does a mul %ecx, which as we just learned, multiplies it's operand by the value in %eax, and then proceeds to store the result of this multiplication in EDX:EAX.  So, regardless of %eax's previous contents, %eax must now be 0.  However that's not all, %edx is 0'd now too, because, even though no overflow occurs, it still overwrites the %edx register with the sign bit(left-most bit) of %eax.  Using this technique we can zero out three registers in only three bytes, whereas by any other method(that I know of) it would have taken at least six.


The div instruction

Div is very similar to mul, in that it takes only one operand and implicitly divides the operand by the value in %eax.  Also like, mul it stores the result of the divide in %eax.  Again, we will require the mathematical side of our brains to figure out how we can take advantage of this instruction.  But first, let's think about what is normally stored in the %eax register.  The %eax register holds the return value of functions and/or syscalls.  Most syscalls that are used in shellcoding will return -1(on failure) or a positive value of some kind, only rarely will they return 0(though it does occur).  So, if we know that after a syscall is performed, %eax will have a non-zero value, and that  the instruction divl %eax will divide %eax by itself, and then store the result in %eax, we can say that executing the divl %eax instruction after a syscall will put the value 1 into %eax.  So...how is this applicable to shellcoding? Well, their is another important thing that %eax is used for, and that is to pass the specific syscall that you would like to call to int $0x80.  It just so happens that the syscall that corresponds to the value 1 is exit().  Now for an example:

      
xorl %ebx,%ebx
mul %ebx
push %edx
pushl   $0x3268732f
pushl   $0x6e69622f
mov %esp, %ebx
push %edx
push %ebx
mov %esp,%ecx
movb $0xb, %al  #execve() syscall, doesn't return at all unless it fails, in which case it returns -1
int $0x80

divl %eax  # -1 / -1 = 1
int $0x80

Now, we have a 3 byte exit function, where as before it was 5 bytes.  However, there is a catch, what if a syscall does return 0?  Well in the odd situation in which that could happen, you could do many different things, like inc %eax, dec %eax, not %eax anything that will make %eax non-zero.  Some people say that exit's are not important in shellcode, because your code gets executed regardless of whether or not it exits cleanly.  They are right too, if you really need to save 3 bytes to fit your shellcode in somewhere, the exit() isn't worth keeping.  However, when your code does finish, it will try to execute whatever was after your last instruction, which will most likely produce a SIG ILL(illegal instruction) which is a rather odd error, and will be logged by the system.  So, an exit() simply adds an extra layer of stealth to your exploit, so that even if it fails or you can't wipe all the logs, at least this part of your presence will be clear.



Unlocking the power of leal

The leal instruction is an often neglected instruction in shellcode, even though it is quite useful.  Consider this short piece of shellcode.

xorl %ecx,%ecx
leal 0x10(%ecx),%eax

This will load the value 17 into eax, and clear all of the extraneous bits of eax.  This occurs because the leal instruction loads a variable of the type long into it's desitination operand.  In it's normal usage, this would load the address of a variable into a register, thus creating a pointer of sorts.  However, since ecx is 0'd and 0+17=17, we load the value 17 into eax instead of any kind of actual address.  In a normal shellcode we would do something like this, to accomplish the same thing:

xorl %eax,%eax
movb $0x10,%eax

I can hear you saying, but that shellcode is a byte shorter than the leal one, and you're quite right.  However, in a real shellcode you may already have to 0 out a register like ecx(or any other register), so the xorl instruction in the leal shellcode isn't counted.  Here's an example:

xorl    %eax,%eax
xorl    %ebx,%ebx
movb    $0x17,%al
int    $0x80
      
xorl %ebx,%ebx
leal 0x17(%ebx),%al
int $0x80

Both of these shellcodes call setuid(0), but one does it in 7 bytes while the other does it in 8.  Again, I hear you saying but that's only one byte it doesn't make that much of a difference, and you're right, here it doesn't make much of a difference(except for in shellcode-size pissing contests =p), but when applied to much larger shellcodes, which have many function calls and need to do things like this frequently, it can save quite a bit of space.



Conclusion

I hope you all learned something, and will go out and apply your knowledge to create smaller and better shellcodes.  If you know who invented  the leal technique, please tell me and I will credit him/her.

A Web Standards Checklist, How to make a proper website

A Web Standards Checklist, How to make a proper website

A web standards checklist

The term web standards can mean different things to different people. For some, it is 'table-free sites', for others it is 'using valid code'. However, web standards are much broader than that. A site built to web standards should adhere to standards (HTML, XHTML, XML, CSS, XSLT, DOM, MathML, SVG etc) and pursue best practices (valid code, accessible code, semantically correct code, user-friendly URLs etc).

In other words, a site built to web standards should ideally be lean, clean, CSS-based, accessible, usable and search engine friendly.

About the checklist

This is not an uber-checklist. There are probably many items that could be added. More importantly, it should not be seen as a list of items that must be addressed on every site that you develop. It is simply a guide that can be used:

* to show the breadth of web standards
* as a handy tool for developers during the production phase of websites
* as an aid for developers who are interested in moving towards web standards

The checklist

1.Quality of code
1. Does the site use a correct Doctype?
2. Does the site use a Character set?
3. Does the site use Valid (X)HTML?
4. Does the site use Valid CSS?
5. Does the site use any CSS hacks?
6. Does the site use unnecessary classes or ids?
7. Is the code well structured?
8. Does the site have any broken links?
9. How does the site perform in terms of speed/page size?
10. Does the site have JavaScript errors?

2. Degree of separation between content and presentation
1. Does the site use CSS for all presentation aspects (fonts, colour, padding, borders etc)?
2. Are all decorative images in the CSS, or do they appear in the (X)HTML?

3. Accessibility for users
1. Are "alt" attributes used for all descriptive images?
2. Does the site use relative units rather than absolute units for text size?
3. Do any aspects of the layout break if font size is increased?
4. Does the site use visible skip menus?
5. Does the site use accessible forms?
6. Does the site use accessible tables?
7. Is there sufficient colour brightness/contrasts?
8. Is colour alone used for critical information?
9. Is there delayed responsiveness for dropdown menus (for users with reduced motor skills)?
10. Are all links descriptive (for blind users)?

4. Accessibility for devices
1. Does the site work acceptably across modern and older browsers?
2. Is the content accessible with CSS switched off or not supported?
3. Is the content accessible with images switched off or not supported?
4. Does the site work in text browsers such as Lynx?
5. Does the site work well when printed?
6. Does the site work well in Hand Held devices?
7. Does the site include detailed metadata?
8. Does the site work well in a range of browser window sizes?

5. Basic Usability
1. Is there a clear visual hierarchy?
2. Are heading levels easy to distinguish?
3. Does the site have easy to understand navigation?
4. Does the site use consistent navigation?
5. Are links underlined?
6. Does the site use consistent and appropriate language?
7. Do you have a sitemap page and contact page? Are they easy to find?
8. For large sites, is there a search tool?
9. Is there a link to the home page on every page in the site?
10. Are visited links clearly defined with a unique colour?

6. Site management
1. Does the site have a meaningful and helpful 404 error page that works from any depth in the site?
2. Does the site use friendly URLs?
3. Do your URLs work without "www"?
4. Does the site have a favicon?

1. Quality of code

1.1 Does the site use a correct Doctype?
A doctype (short for 'document type declaration') informs the validator which version of (X)HTML you're using, and must appear at the very top of every web page. Doctypes are a key component of compliant web pages: your markup and CSS won't validate without them.
CODE
http://www.alistapart.com/articles/doctype/


More:
CODE
http://www.w3.org/QA/2002/04/valid-dtd-list.html

CODE
http://css.maxdesign.com.au/listamatic/about-boxmodel.htm

CODE
http://gutfeldt.ch/matthias/articles/doctypeswitch.html


1.2 Does the site use a Character set?
If a user agent (eg. a browser) is unable to detect the character encoding used in a Web document, the user may be presented with unreadable text. This information is particularly important for those maintaining and extending a multilingual site, but declaring the character encoding of the document is important for anyone producing XHTML/HTML or CSS.
CODE
http://www.w3.org/International/tutorials/tutorial-char-enc/


More:
CODE
http://www.w3.org/International/O-charset.html


1.3 Does the site use Valid (X)HTML?
Valid code will render faster than code with errors. Valid code will render better than invalid code. Browsers are becoming more standards compliant, and it is becoming increasingly necessary to write valid and standards compliant HTML.
CODE
http://www.maxdesign.com.au/presentation/sit2003/06.htm


More:
CODE
http://validator.w3.org/


1.4 Does the site use Valid CSS?
You need to make sure that there aren't any errors in either your HTML or your CSS, since mistakes in either place can result in botched document appearance.
CODE
http://www.meyerweb.com/eric/articles/webrev/199904.html


More:
CODE
http://jigsaw.w3.org/css-validator/


1.5 Does the site use any CSS hacks?
Basically, hacks come down to personal choice, the amount of knowledge you have of workarounds, the specific design you are trying to achieve.
CODE
http://www.mail-archive.com/wsg@webstandardsgroup.org/msg05823.html


More:
CODE
http://css-discuss.incutio.com/?page=CssHack

CODE
http://css-discuss.incutio.com/?page=ToHackOrNotToHack

CODE
http://centricle.com/ref/css/filters/


1.6 Does the site use unnecessary classes or ids?
I've noticed that developers learning new skills often end up with good CSS but poor XHTML. Specifically, the HTML code tends to be full of unnecessary divs and ids. This results in fairly meaningless HTML and bloated style sheets.
CODE
http://www.clagnut.com/blog/228/


1.7 Is the code well structured?
Semantically correct markup uses html elements for their given purpose. Well structured HTML has semantic meaning for a wide range of user agents (browsers without style sheets, text browsers, PDAs, search engines etc.)
CODE
http://www.maxdesign.com.au/presentation/benefits/index04.htm


More:
CODE
http://www.w3.org/2003/12/semantic-extractor.html


1.8 Does the site have any broken links?
Broken links can frustrate users and potentially drive customers away. Broken links can also keep search engines from properly indexing your site.

More:
CODE
http://validator.w3.org/checklink


1.9 How does the site perform in terms of speed/page size?
Don't make me wait... That's the message users give us in survey after survey. Even broadband users can suffer the slow-loading blues.
CODE
http://www.websiteoptimization.com/speed/


1.10 Does the site have JavaScript errors?
Internet Explore for Windows allows you to turn on a debugger that will pop up a new window and let you know there are javascript errors on your site. This is available under 'Internet Options' on the Advanced tab. Uncheck 'Disable script debugging'.

2. Degree of separation between content and presentation

2.1 Does the site use CSS for all presentation aspects (fonts, colour, padding, borders etc)?
Use style sheets to control layout and presentation.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-style-sheets


2.2 Are all decorative images in the CSS, or do they appear in the (X)HTML?
The aim for web developers is to remove all presentation from the html code, leaving it clean and semantically correct.
CODE
http://www.maxdesign.com.au/presentation/benefits/index07.htm


3. Accessibility for users

3.1 Are "alt" attributes used for all descriptive images?
Provide a text equivalent for every non-text element
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-text-equivalent


3.2 Does the site use relative units rather than absolute units for text size?
Use relative rather than absolute units in markup language attribute values and style sheet property values'.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-relative-units


More:
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-relative-units

CODE
http://www.clagnut.com/blog/348/


3.3 Do any aspects of the layout break if font size is increased?
Try this simple test. Look at your website in a browser that supports easy incrementation of font size. Now increase your browser's font size. And again. And again... Look at your site. Does the page layout still hold together? It is dangerous for developers to assume that everyone browses using default font sizes.
3.4 Does the site use visible skip menus?

A method shall be provided that permits users to skip repetitive navigation links.
CODE
http://www.section508.gov/index.cfm?FuseAction=Content&ID=12


Group related links, identify the group (for user agents), and, until user agents do so, provide a way to bypass the group.
CODE
http://www.w3.org/TR/WCAG10-TECHS/#tech-group-links


...blind visitors are not the only ones inconvenienced by too many links in a navigation area. Recall that a mobility-impaired person with poor adaptive technology might be stuck tabbing through that morass.
CODE
http://joeclark.org/book/sashay/serialization/Chapter08.html#h4-2020


More:
CODE
http://www.niehs.nih.gov/websmith/508/o.htm


3.5 Does the site use accessible forms?
Forms aren't the easiest of things to use for people with disabilities. Navigating around a page with written content is one thing, hopping between form fields and inputting information is another.
CODE
http://www.htmldog.com/guides/htmladvanced/forms/


More:
CODE
http://www.webstandards.org/learn/tutorials/accessible-forms/01-accessible-forms.html

CODE
http://www.accessify.com/tools-and-wizards/accessible-form-builder.asp

CODE
http://accessify.com/tutorials/better-accessible-forms.asp


3.6 Does the site use accessible tables?
For data tables, identify row and column headers... For data tables that have two or more logical levels of row or column headers, use markup to associate data cells and header cells.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-table-headers


More:
CODE
http://www.bcc.ctc.edu/webpublishing/ada/resources/tables.asp

CODE
http://www.accessify.com/tools-and-wizards/accessible-table-builder_step1.asp

CODE
http://www.webaim.org/techniques/tables/


3.7 Is there sufficient colour brightness/contrasts?
Ensure that foreground and background colour combinations provide sufficient contrast when viewed by someone having colour deficits.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-colour-contrast


More:
CODE
http://www.juicystudio.com/services/colourcontrast.asp


3.8 Is colour alone used for critical information?
Ensure that all information conveyed with colour is also available without colour, for example from context or markup.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-colour-convey


There are basically three types of colour deficiency; Deuteranope (a form of red/green colour deficit), Protanope (another form of red/green colour deficit) and Tritanope (a blue/yellow deficit- very rare).

More:
CODE
http://colourfilter.wickline.org/

CODE
http://www.toledo-bend.com/colourblind/Ishihara.html

CODE
http://www.vischeck.com/vischeck/vischeckURL.php


3.9 Is there delayed responsiveness for dropdown menus?
Users with reduced motor skills may find dropdown menus hard to use if responsiveness is set too fast.

3.10 Are all links descriptive?
Link text should be meaningful enough to make sense when read out of context - either on its own or as part of a sequence of links. Link text should also be terse.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-meaningful-links


4. Accessibility for devices.

4.1 Does the site work acceptably across modern and older browsers?

Before starting to build a CSS-based layout, you should decide which browsers to support and to what level you intend to support them.
CODE
http://www.maxdesign.com.au/presentation/process/index_step01.cfm



4.2 Is the content accessible with CSS switched off or not supported?
Some people may visit your site with either a browser that does not support CSS or a browser with CSS switched off. In content is structured well, this will not be an issue.

4.3 Is the content accessible with images switched off or not supported?
Some people browse websites with images switched off - especially people on very slow connections. Content should still be accessible for these people.

4.4 Does the site work in text browsers such as Lynx?
This is like a combination of images and CSS switched off. A text-based browser will rely on well structured content to provide meaning.

More:
CODE
http://www.delorie.com/web/lynxview


4.5 Does the site work well when printed?
You can take any (X)HTML document and simply style it for print, without having to touch the markup.
CODE
http://www.alistapart.com/articles/goingtoprint/


More:
CODE
http://www.d.umn.edu/itss/support/Training/Online/webdesign/css.html#print


4.6 Does the site work well in Hand Held devices?
This is a hard one to deal with until hand held devices consistently support their correct media type. However, some layouts work better in current hand-held devices. The importance of supporting hand held devices will depend on target audiences.

4.7 Does the site include detailed metadata?
Metadata is machine understandable information for the web
CODE
http://www.w3.org/Metadata/


Metadata is structured information that is created specifically to describe another resource. In other words, metadata is 'data about data'.


4.8 Does the site work well in a range of browser window sizes?
It is a common assumption amongst developers that average screen sizes are increasing. Some developers assume that the average screen size is now 1024px wide. But what about users with smaller screens and users with hand held devices? Are they part of your target audience and are they being disadvantaged?

5. Basic Usability
5.1 Is there a clear visual hierarchy?
Organise and prioritise the contents of a page by using size, prominence and content relationships.
CODE
http://www.great-web-design-tips.com/web-site-design/165.html


5.2 Are heading levels easy to distinguish?
Use header elements to convey document structure and use them according to specification.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-logical-headings


5.3 Is the site's navigation easy to understand?
Your navigation system should give your visitor a clue as to what page of the site they are currently on and where they can go next.
CODE
http://www.1stsitefree.com/design_nav.htm


5.4 Is the site's navigation consistent?
If each page on your site has a consistent style of presentation, visitors will find it easier to navigate between pages and find information
CODE
http://www.juicystudio.com/tutorial/accessibility/navigation.asp


5.5 Does the site use consistent and appropriate language?
The use of clear and simple language promotes effective communication. Trying to come across as articulate can be as difficult to read as poorly written grammar, especially if the language used isn't the visitor's primary language.
CODE
http://www.juicystudio.com/tutorial/accessibility/clear.asp


5.6 Does the site have a sitemap page and contact page? Are they easy to find?
Most site maps fail to convey multiple levels of the site's information architecture. In usability tests, users often overlook site maps or can't find them. Complexity is also a problem: a map should be a map, not a navigational challenge of its own.
CODE
http://www.useit.com/alertbox/20020106.html


5.7 For large sites, is there a search tool?
While search tools are not needed on smaller sites, and some people will not ever use them, site-specific search tools allow users a choice of navigation options.

5.8 Is there a link to the home page on every page in the site?
Some users like to go back to a site's home page after navigating to content within a site. The home page becomes a base camp for these users, allowing them to regroup before exploring new content.

5.9 Are links underlined?
To maximise the perceived affordance of clickability, colour and underline the link text. Users shouldn't have to guess or scrub the page to find out where they can click.
CODE
http://www.useit.com/alertbox/20040510.html


5.10 Are visited links clearly defined?
Most important, knowing which pages they've already visited frees users from unintentionally revisiting the same pages over and over again.
CODE
http://www.useit.com/alertbox/20040503.html


6. Site management

6.1 Does the site have a meaningful and helpful 404 error page that works from any depth in the site?
You've requested a page - either by typing a URL directly into the address bar or clicking on an out-of-date link and you've found yourself in the middle of cyberspace nowhere. A user-friendly website will give you a helping hand while many others will simply do nothing, relying on the browser's built-in ability to explain what the problem is.
CODE
http://www.alistapart.com/articles/perfect404/


6.2 Does the site use friendly URLs?
Most search engines (with a few exceptions - namely Google) will not index any pages that have a question mark or other character (like an ampersand or equals sign) in the URL... what good is a site if no one can find it?
CODE
http://www.sitepoint.com/article/search-engine-friendly-urls


One of the worst elements of the web from a user interface standpoint is the URL. However, if they're short, logical, and self-correcting, URLs can be acceptably usable
CODE
http://www.merges.net/theory/20010305.html


More:
CODE
http://www.sitepoint.com/article/search-engine-friendly-urls

CODE
http://www.websitegoodies.com/article/32

CODE
http://www.merges.net/theory/20010305.html


6.3 Does the site's URL work without "www"?
While this is not critical, and in some cases is not even possible, it is always good to give people the choice of both options. If a user types your domain name without the www and gets no site, this could disadvantage both the user and you.
6.4 Does the site have a favicon?

A Favicon is a multi-resolution image included on nearly all professionally developed sites. The Favicon allows the webmaster to further promote their site, and to create a more customized appearance within a visitor's browser.
CODE
http://www.favicon.com/


Favicons are definitely not critical. However, if they are not present, they can cause 404 errors in your logs (site statistics). Browsers like IE will request them from the server when a site is bookmarked. If a favicon isn't available, a 404 error may be generated. Therefore, having a favicon could cut down on favicon specific 404 errors. The same is true of a 'robots.txt' file.

Short Tut for Real Media

You may find this helpful if you donwload hundreds of short episodes in rm format like me and tired of double-click to open next files.

Very easy. Use notepad to open a new file, type this inside:
file://link to file1
file://link to file2
(type as many as you want)
Close file. Rename it to FileName.rm

Then you`re done!!!!

Ex:
I put my playlist file here: C:\Movies\7VNR
And the movie files are in C:\Movies\7VNR\DragonBall

Then inside my playlist file I`ll have something like this:

file://DragonBall/db134.rm
file://DragonBall/db135.rm
file://DragonBall/db136.rm
file://DragonBall/db137.rm
file://DragonBall/db138.rm

10 Fast and Free Security Enhancements

Before you spend a dime on security, there are many precautions you can take that will protect you against the most common threats.

1. Check Windows Update and Office Update regularly (_http://office.microsoft.com/productupdates); have your Office CD ready. Windows Me, 2000, XP, Vista and Windows 7 users can configure automatic updates. Click on the Automatic Updates tab in the System control panel and choose the appropriate options.

2. Install a personal firewall. Both SyGate (_www.sygate.com) and ZoneAlarm (_www.zonelabs.com) offer free versions.

3. Install a free spyware blocker. Our Editors' Choice ("Spyware," April 22) was SpyBot Search & Destroy (_http://security.kolla.de). SpyBot is also paranoid and ruthless in hunting out tracking cookies.

4. Block pop-up spam messages in Windows NT, 2000, or XP by disabling the Windows Messenger service (this is unrelated to the instant messaging program). Open Control Panel | Administrative Tools | Services and you'll see Messenger. Right-click and go to Properties. Set Start-up Type to Disabled and press the Stop button. Bye-bye, spam pop-ups! Any good firewall will also stop them.

5. Use strong passwords and change them periodically. Passwords should have at least seven characters; use letters and numbers and have at least one symbol. A decent example would be f8izKro@l. This will make it much harder for anyone to gain access to your accounts.

6. If you're using Outlook or Outlook Express, use the current version or one with the Outlook Security Update installed. The update and current versions patch numerous vulnerabilities.

7. Buy antivirus software and keep it up to date. If you're not willing to pay, try Grisoft AVG Free Edition (Grisoft Inc., w*w.grisoft.com). And doublecheck your AV with the free, online-only scanners available at w*w.pandasoftware.com/activescan and _http://housecall.trendmicro.com.

8. If you have a wireless network, turn on the security features: Use MAC filtering, turn off SSID broadcast, and even use WEP with the biggest key you can get. For more, check out our wireless section or see the expanded coverage in Your Unwired World in our next issue.

9. Join a respectable e-mail security list, such as the one found at our own Security Supersite at _http://security.ziffdavis.com, so that you learn about emerging threats quickly and can take proper precautions.

10. Be skeptical of things on the Internet. Don't assume that e-mail "From:" a particular person is actually from that person until you have further reason to believe it's that person. Don't assume that an attachment is what it says it is. Don't give out your password to anyone, even if that person claims to be from "support."

10 reasons why PCs crash U must Know

Fatal error: the system has become unstable or is busy," it says. "Enter to return to Windows or press Control-Alt-Delete to restart your computer. If you do this you will lose any unsaved information in all open applications."

You have just been struck by the Blue Screen of Death. Anyone who uses Mcft Windows will be familiar with this. What can you do? More importantly, how can you prevent it happening?

1. Hardware conflict

The number one reason why Windows crashes is hardware conflict. Each hardware device communicates to other devices through an interrupt request channel (IRQ). These are supposed to be unique for each device.

For example, a printer usually connects internally on IRQ 7. The keyboard usually uses IRQ 1 and the floppy disk drive IRQ 6. Each device will try to hog a single IRQ for itself.

If there are a lot of devices, or if they are not installed properly, two of them may end up sharing the same IRQ number. When the user tries to use both devices at the same time, a crash can happen. The way to check if your computer has a hardware conflict is through the following route:

* Start-Settings-Control Panel-System-Device Manager.

Often if a device has a problem a yellow '!' appears next to its description in the Device Manager. Highlight Computer (in the Device Manager) and press Properties to see the IRQ numbers used by your computer. If the IRQ number appears twice, two devices may be using it.

Sometimes a device might share an IRQ with something described as 'IRQ holder for PCI steering'. This can be ignored. The best way to fix this problem is to remove the problem device and reinstall it.

Sometimes you may have to find more recent drivers on the internet to make the device function properly. A good resource is www.driverguide.com. If the device is a soundcard, or a modem, it can often be fixed by moving it to a different slot on the motherboard (be careful about opening your computer, as you may void the warranty).

When working inside a computer you should switch it off, unplug the mains lead and touch an unpainted metal surface to discharge any static electricity.

To be fair to Mcft, the problem with IRQ numbers is not of its making. It is a legacy problem going back to the first PC designs using the IBM 8086 chip. Initially there were only eight IRQs. Today there are 16 IRQs in a PC. It is easy to run out of them. There are plans to increase the number of IRQs in future designs.

2. Bad Ram

Ram (random-access memory) problems might bring on the blue screen of death with a message saying Fatal Exception Error. A fatal error indicates a serious hardware problem. Sometimes it may mean a part is damaged and will need replacing.

But a fatal error caused by Ram might be caused by a mismatch of chips. For example, mixing 70-nanosecond (70ns) Ram with 60ns Ram will usually force the computer to run all the Ram at the slower speed. This will often crash the machine if the Ram is overworked.

One way around this problem is to enter the BIOS settings and increase the wait state of the Ram. This can make it more stable. Another way to troubleshoot a suspected Ram problem is to rearrange the Ram chips on the motherboard, or take some of them out. Then try to repeat the circumstances that caused the crash. When handling Ram try not to touch the gold connections, as they can be easily damaged.

Parity error messages also refer to Ram. Modern Ram chips are either parity (ECC) or non parity (non-ECC). It is best not to mix the two types, as this can be a cause of trouble.

EMM386 error messages refer to memory problems but may not be connected to bad Ram. This may be due to free memory problems often linked to old Dos-based programmes.

3. BIOS settings

Every motherboard is supplied with a range of chipset settings that are decided in the factory. A common way to access these settings is to press the F2 or delete button during the first few seconds of a boot-up.

Once inside the BIOS, great care should be taken. It is a good idea to write down on a piece of paper all the settings that appear on the screen. That way, if you change something and the computer becomes more unstable, you will know what settings to revert to.

A common BIOS error concerns the CAS latency. This refers to the Ram. Older EDO (extended data out) Ram has a CAS latency of 3. Newer SDRam has a CAS latency of 2. Setting the wrong figure can cause the Ram to lock up and freeze the computer's display.

Mcft Windows is better at allocating IRQ numbers than any BIOS. If possible set the IRQ numbers to Auto in the BIOS. This will allow Windows to allocate the IRQ numbers (make sure the BIOS setting for Plug and Play OS is switched to 'yes' to allow Windows to do this.).

4. Hard disk drives

After a few weeks, the information on a hard disk drive starts to become piecemeal or fragmented. It is a good idea to defragment the hard disk every week or so, to prevent the disk from causing a screen freeze. Go to

* Start-Programs-Accessories-System Tools-Disk Defragmenter

This will start the procedure. You will be unable to write data to the hard drive (to save it) while the disk is defragmenting, so it is a good idea to schedule the procedure for a period of inactivity using the Task Scheduler.

The Task Scheduler should be one of the small icons on the bottom right of the Windows opening page (the desktop).

Some lockups and screen freezes caused by hard disk problems can be solved by reducing the read-ahead optimisation. This can be adjusted by going to

* Start-Settings-Control Panel-System Icon-Performance-File System-Hard Disk.

Hard disks will slow down and crash if they are too full. Do some housekeeping on your hard drive every few months and free some space on it. Open the Windows folder on the C drive and find the Temporary Internet Files folder. Deleting the contents (not the folder) can free a lot of space.

Empty the Recycle Bin every week to free more space. Hard disk drives should be scanned every week for errors or bad sectors. Go to

* Start-Programs-Accessories-System Tools-ScanDisk

Otherwise assign the Task Scheduler to perform this operation at night when the computer is not in use.

5. Fatal OE exceptions and VXD errors

Fatal OE exception errors and VXD errors are often caused by video card problems.

These can often be resolved easily by reducing the resolution of the video display. Go to

* Start-Settings-Control Panel-Display-Settings

Here you should slide the screen area bar to the left. Take a look at the colour settings on the left of that window. For most desktops, high colour 16-bit depth is adequate.

If the screen freezes or you experience system lockups it might be due to the video card. Make sure it does not have a hardware conflict. Go to

* Start-Settings-Control Panel-System-Device Manager

Here, select the + beside Display Adapter. A line of text describing your video card should appear. Select it (make it blue) and press properties. Then select Resources and select each line in the window. Look for a message that says No Conflicts.

If you have video card hardware conflict, you will see it here. Be careful at this point and make a note of everything you do in case you make things worse.

The way to resolve a hardware conflict is to uncheck the Use Automatic Settings box and hit the Change Settings button. You are searching for a setting that will display a No Conflicts message.

Another useful way to resolve video problems is to go to

* Start-Settings-Control Panel-System-Performance-Graphics

Here you should move the Hardware Acceleration slider to the left. As ever, the most common cause of problems relating to graphics cards is old or faulty drivers (a driver is a small piece of software used by a computer to communicate with a device).

Look up your video card's manufacturer on the internet and search for the most recent drivers for it.

6. Viruses

Often the first sign of a virus infection is instability. Some viruses erase the boot sector of a hard drive, making it impossible to start. This is why it is a good idea to create a Windows start-up disk. Go to

* Start-Settings-Control Panel-Add/Remove Programs

Here, look for the Start Up Disk tab. Virus protection requires constant vigilance.

A virus scanner requires a list of virus signatures in order to be able to identify viruses. These signatures are stored in a DAT file. DAT files should be updated weekly from the website of your antivirus software manufacturer.

An excellent antivirus programme is McAfee VirusScan by Network Associates ( www.nai.com). Another is Norton AntiVirus 2000, made by Symantec ( www.symantec.com).

7. Printers

The action of sending a document to print creates a bigger file, often called a postscript file.

Printers have only a small amount of memory, called a buffer. This can be easily overloaded. Printing a document also uses a considerable amount of CPU power. This will also slow down the computer's performance.

If the printer is trying to print unusual characters, these might not be recognised, and can crash the computer. Sometimes printers will not recover from a crash because of confusion in the buffer. A good way to clear the buffer is to unplug the printer for ten seconds. Booting up from a powerless state, also called a cold boot, will restore the printer's default settings and you may be able to carry on.

8. Software

A common cause of computer crash is faulty or badly-installed software. Often the problem can be cured by uninstalling the software and then reinstalling it. Use Norton Uninstall or Uninstall Shield to remove an application from your system properly. This will also remove references to the programme in the System Registry and leaves the way clear for a completely fresh copy.

The System Registry can be corrupted by old references to obsolete software that you thought was uninstalled. Use Reg Cleaner by Jouni Vuorio to clean up the System Registry and remove obsolete entries. It works on Windows 95, Windows 98, Windows 98 SE (Second Edition), Windows Millennium Edition (ME), NT4 and Windows 2000.

Read the instructions and use it carefully so you don't do permanent damage to the Registry. If the Registry is damaged you will have to reinstall your operating system. Reg Cleaner can be obtained from www.jv16.org

Often a Windows problem can be resolved by entering Safe Mode. This can be done during start-up. When you see the message "Starting Windows" press F4. This should take you into Safe Mode.

Safe Mode loads a minimum of drivers. It allows you to find and fix problems that prevent Windows from loading properly.

Sometimes installing Windows is difficult because of unsuitable BIOS settings. If you keep getting SUWIN error messages (Windows setup) during the Windows installation, then try entering the BIOS and disabling the CPU internal cache. Try to disable the Level 2 (L2) cache if that doesn't work.

Remember to restore all the BIOS settings back to their former settings following installation.

9. Overheating

Central processing units (CPUs) are usually equipped with fans to keep them cool. If the fan fails or if the CPU gets old it may start to overheat and generate a particular kind of error called a kernel error. This is a common problem in chips that have been overclocked to operate at higher speeds than they are supposed to.

One remedy is to get a bigger better fan and install it on top of the CPU. Specialist cooling fans/heatsinks are available from www.computernerd.com or www.coolit.com

CPU problems can often be fixed by disabling the CPU internal cache in the BIOS. This will make the machine run more slowly, but it should also be more stable.

10. Power supply problems

With all the new construction going on around the country the steady supply of electricity has become disrupted. A power surge or spike can crash a computer as easily as a power cut.

If this has become a nuisance for you then consider buying a uninterrupted power supply (UPS). This will give you a clean power supply when there is electricity, and it will give you a few minutes to perform a controlled shutdown in case of a power cut.

It is a good investment if your data are critical, because a power cut will cause any unsaved data to be lost.