Fuck with the registry at your own risk - and it is a true risk.
Whilst I am no super-geek when it comes to PC's I am fairly confident and posess a pretty good array of knowledge on them when it comes to solving problems. I read a lot about something before I do it and gather as much intel as I can before doing something...
When I had a major virus buttfucking my system a year or so ago, I spent a long time sorting the registry out, modifying and removing, entry by entry, and all was going fine. Then one ill-descision later, my registry was fucked and it was re-installation time