Need to find "free"comp registry scanner and cleaner.Any Idea's?

I'm looking for a web site that does not charge for scanning and cleaning out my computer registry.does anyone know any of those sites.I only find the one's that wnat me tyo purchase their product.I think there has to be a free site that I can download,and it would do the same as the other one that I would have to pay for.Did anyone find such site yet?