I don't see any suggestions that I would consider definitive, so...I would probably run chkdsk /r and then run sfc /scannow as suggested in the link.
Start/Run...type chkdsk /r (with space between k and /) and hit Enter. In response to onscreen query, type Y and hit Enter. Reboot system and chkdsk will run to completion and then reboot the system.
Start/Run...type sfc /scannow (with space between c and /) and hit Enter. Have your XP install CD handy, if possible, since such may be requested as a source of replacement system files.