Press F8 Before the Windows XP Splash Screen

Starting your computer in Windows XP Safe Mode can help you diagnose and solve many serious problems, especially when starting normally is not possible.
To begin entering Windows XP Safe Mode, turn your PC on or restart it.
Just before the Windows XP splash screen shown above appears, press the F8 key to enter the Windows Advanced Options Menu.

Choose a Windows XP Safe Mode Option

You should now see the Windows Advanced Options Menu screen. If not, you may have missed the small window of opportunity to press F8 from Step #1 and Windows XP is probably now continuing to boot normally if it's able to. If this is the case, just restart your computer and try pressing F8 again.
Here you are presented with three variations of Windows XP Safe Mode you may enter:

• Safe Mode - This is the default option and is usually the best choice. This mode will load only the absolute minimum processes necessary to start Windows XP.
  
• Safe Mode with Networking - This option loads the same processes as Safe Mode but also includes those that allow the networking functions in Windows XP to work. This is valuable if you may need to access the Internet or your local network while troubleshooting in Safe Mode.
  
• Safe Mode with Command Prompt - This flavor of Safe Mode also loads a minimum set of processes but will allow access to a command prompt. This is a valuable option if more advanced troubleshooting is necessary. This Windows XP Safe Mode option is a little different so check out the Windows XP Safe Mode with Command Prompt instructions for more information.

Using the arrow keys on your keyboard, highlight either the Safe Mode or Safe Mode with Networking option and press Enter.