Dudes, i had the same problem, I searched online and I found a blog posting from Charles white, my problem was a computer with viruses, I used avast to clean them and did a reboot clean, my mistake was to make the settings to erase the virus files instead of repairing them or moving them to quarantine, so I messed up windows and couldn't even get in safe mode, I tried to repair it from the xp install disk, after the first reboot I got the blue screen of death, and I was all frustrated, I was not comfortable using the repair console and writing down commands but I still took the chance, this guy posted the way to repair your xp and it worked, I read 9 pages of this blog here without a solution until I tried Charles white's solution, it worked for me, and I hope it works for you, here is the link:
http://webcast.broadcastnewsroom.com/articles/vie...cle.jsp?id=8658-0#
I hope it works for you too!
Sal