Using the Last Known Good Configuration Boot Option
If you experience difficulty starting your Windows Server 2003 operating system after you install a new driver or change a driver configuration, you can use the Last Known Good Configuration advanced startup options. If you use this boot option, the registry configuration reverts to the condition it was in before you made the changes that prevented the operating system from starting normally. Additionally, if you use this option, you will lose all configuration changes that were made since you last successfully logged on to your system. When you successfully log on after you make changes that affect the registry, the Last Known Good Configuration option cannot roll back those changes.
For more information about the Last Known Good Configuration options and other advanced startup options, see Microsoft Knowledge Base article 325375, "HOW TO: Troubleshoot Startup Problems in Windows Server 2003."