Scott,
There is a freeware program called "RegScrub" that I use all the time with absolutely no problems. I run it in the fully automatic mode and it has bailed me out on more than one occaision. It automatically backs up every change to the registry and if something does go wrong you can restore to any previous values.
It is not as aggressive as most reistry cleaners, which are very dangerous unless you really know what you are doing. http://home.carolina.rr.com/lexunfreeware

Good luck,
Walt