Just read the original post:

If you are keeping the original drive just for software reasons then . You cannot just toss around hard drives from one computer to another without reinstalling the OS. It will not boot unless the IDE controller almost matches the original. (i.e. earlier model SiS chipset to a new model SiS)

The fact that you have kept the drive around from all the way back to 98 then over to 2000, and then XP, the computer will have some serious lag issues going on by doing that.

Just a technicians $.02

Tony 1998 SVT Contour (B/MB) #542 3L 1998 SVT Contour (SF/MB) #1266 parts car 2000 SVT Contour (SF/MB) #1533 3L swap to begin!