> A friend's laptop was working fine. She left it at home and her daughter or
> grandson installed something (such as a game or codec) on the machine.
>
> Now the machine won't even boot up. It boots for a while, a BSOD, then it
> reboots. Doesn't matter if normal, safe mode, etc is used - the machine BSODs
> and reboots. A cursory search with Google turns up that the problem probably is
> a configuration/driver error.
>
> I took the hard drive out, put it in an external enclosure, and scanned the
> drive. The drive physically seems fine.
>
> Is there a program I can run on the drive that will scan the drive and fix any
> driver/configuration problems? The program would need to be able to look at the
> external drive, not the current boot drive.
>
> Any help would be appreciated.
What stop error is it? 0x0000007a? 0x0000007e?

Did you try Last Known Good config? Try booting into safe mode (if you can) and select NO which will take you to system restore. Pick a time before the F-up occurred.