Its a lost cause... all "reg cleaners" do is mess things up (sooner or later!)
The Windows Registry is such a MESS that no software will ever be able to properly clean it up for you.
So... just install your OS again FRESH, and avoid installing tons of junk software!
and then... use THIS excellent registry backup / optimizer utility:
http://www.larshederer.homepage.t-online.de/erunt/