Start XP with last known good configuration

INTRODUCTION
This article describes how to use the Last Known Good Configuration feature in Windows XP. The Last Known Good Configuration feature is a recovery option that you can use to start your computer by using the most recent settings that worked. The Last Known Good Configuration feature restores registry information and driver settings that were in effect the last time the computer started successfully. Use the Last Known Good Configuration feature when you cannot start Windows XP after you make a change to your computer, or when you suspect that a change that you just made may cause a problem. For example, you can use this feature if you cannot start Windows XP after you install a new driver for your video adapter, or if you installed an incorrect driver and have not yet restarted your computer. When you start your computer by using the Last Known Good Configuration feature, Windows XP restores information in the following registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSetNote Any changes that were made to other registry keys remain.
http://support.microsoft.com/default.aspx?scid=kb;en-us;307852