Thank you very much for you both's reponse. I thought that if we create the emergency repair disk in windows 2000, we could restore the system with the last hardware config based on what we have on the emergency repair disk, and it also backs up the registry so in case if the registry is corrupted. I wonder how we could restore the system with Windows XP CD back to the when the system was running properly if we run into a registry corrupted situation. Thanks in advance.