I'm a programmer, and I can tell you that when this happens to me, I just scrap everything, reload the OS and copy the back ups. *Nuke 'em from orbit. It's the only way to be sure. *
I actually have never needed to reinstall the OS, I generally try to avoid it as much as possible, largely so I can learn more about the system. It would sure as shit save me time, though.
Link
Vosyl
That ultra-dramatic change in tone and perspective. Could almost be me.