Registry cleaner and PC utility

Two registry cleaners and PC clean up utilities that I like are Ccleaner www.ccleaner.com and Advanced System Care
www.iobit.com/advancedwindowscareper.html

Free Windows registry cleaner

Here is a free registry cleaner.
http://www.eusing.com/free_registry_cleaner/registry_cleaner.htm

Make sure you go to Start, Accessories, System Tools, System Restore and set a restore point first.