If you have a hard disk and after a few reinstalls of Windows XP you keep getting:
Windows XP could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM
Check your hard disk with your manufacturer’s test software (like PowerMax in Maxtor’s case), the hard disk might just be dying. It seems to be in my case. Best part, it is already a RMA replacement drive for my previously dying hard disk. Got to love that. Was a refurbished one they sent me. *sigh*
Might as well go Seagate by now.