Windows XP could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM

I am getting this error when trying to boot Windows XP:

Windows XP could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM

It further instructs me to use the original Startup CD-ROM and select r to start repair.

Well, I did just that (using the original startup CD), but then it complains that it could not find any Windows on the hard drive.

This is weird, because from the same hard drive I can boot Windows 2000, which sees the Windows XP partition as drive I:, which seems healthy and contains all system files (it used to work, I don't know what happened to it), including \WINDOWS\SYSTEM32\CONFIG\SYSTEM.

I found this Microsoft resource which explains in detail how to recover from a corrupted registry that prevents Windows XP from starting, but being able to select r from the Recovery Console is pre-requisite and, as I explained above, Microsoft's original startup CD can't let me proceed with selecting r.

Any idea how to recover from this, without having to do a complete re-install?

1) Have a backup? If so, restore from the backup

2) The SYSTEM file may be corrupted. Try running a CHKDSK x: /f /r on the Windows XP partition from Windows 2000, or else CHKDSK x: /f /p from the XP Recovery Console (may need to repeat on the recovery console).

In my experience, it's about a 50/50 shot as to using the repair option on XP. Sometimes it works, sometimes it doesn't. Best I can suggest is try