Help with virus aftermath

I am working on a friend's computer. It is running XP professional, SP2.

It got a nasty case of vundo and assorted other associated downloaders/trojans.

I had to move the hard drive to my computer to clean off most of the virus files, and then put it back to run everything again to clean up virus stuff in the registry and whatever else I couldn't access from my machine. I used AVG, Super AntiSpyware, MalwareBytes AntiMalware, and the ComboFix utility.

It seems to be clean now, but every time the computer is turned back on, it starts with the error screen saying that windows didn't start last time, and do I want to start in safe mode or start normally. Aside from this, everything else is working fine, and there are no traces of any virus.

Any idea what might need to be fixed to correct this? I am currently running the system file checker (sfc /scannow) to see if it will fix anything, but aside from that, I'm at a loss. Thanks.