If you have a genuine MS XP CDROM, use it to start the computer into the Recovery
Console and then run checkdisk /r to check for and repair file system errors.
If no XP CDROM but have a floppy disk drive, then use the 6-boot floppy utility to
make a set of 6 boot floppies. They have the Recovery Console on them:
http://support.microsoft.com/kb/310994/en-us
