Quote Originally Posted by Beirut
The HD in his rig now has a mondo corrupted version of XP Pro in it. (He bought the HD used with XP Pro on it and put it in the new rig he had built.) He gets the BSOD every time he sneezes.
Windows' registry doesn't know what to make of it if you transplant a HD from one machine to another with different hardware. That can be solved if the old registry entries are deleted and the hardware recognition process is started. But it's difficult and shouldn't be tried if you don't know what you do.
That's why reinstalling is best. If you boot the CD you need to choose the installation process and then you'll get the options to repair, reformat or overwrite.