You could try Microsoft's online Pc tuneup software, Safety Live Onecare.
"Get a free PC safety scan
Windows Live OneCare safety scanner is a free service designed to help ensure the health of your PC.
* Check for and remove viruses
* Get rid of junk on your hard disk
* Improve your PC's performance "
http://onecare.live.com/site/en-us/default.htm
Snapfiles is another good source for advice on freeware downloads in ALL catergories, the link here is to the registry software section.
http://www.snapfiles.com/Freeware/sy...wregtools.html
www.download.com also offer reviews / downloads with Registry Mechanic being the Top Rated in the Shareware section.