Windows What's going on? Has a crash killed Windows?

Well I've had an email from my dad this evening detailing a problem he's experienced.

The following is an excerpt of the email:

"I was processing an MPEG file from my old analogue videos - the software got to the end of the job and then crashed and froze Windows. I had to power off and now when Windows tries to start I get the screen about safe mode, previous Windows config, etc. Whichever option I choose the computer reboots once the XP flash screen has been displayed."

I've beeen to see it and it's just sitting in a continual loop - if you let it - of getting just past the XP flash screen, then resetting. The monitor even goes into power saving briefly....

What on earth is going on? Any help would be greatfully accepted

 

I'd usually say that your registry hives are probbably kefuzled. You can try to restore them (if you had system restore enabled) using this article:
http://support.microsoft.com/?id=kb;en-us;Q307545

But I would have expected an error before getting the welcome or boot loader screens.

 

in startup try booting into last known working config