You could also try CCleaner, which I've used a few times to clean up the registry and to uninstall some software (when Control Panel Add/Remove Programs wouldn't populate - I uninstalled some things I wasn't using with CCleaner and then Add/Remove worked again!).

(You can download it from - amongst other places - CNet here: CCleaner).

I'd use the Registry button and let it clean things up there, but also have a look under Tools for the uninstall programs to see if there's anything odd left there.

Mick