Anything you'll see an ad for is just to get your money mainly and some of those are malware so it would be counter productive if you're trying to rid yourself of it. CCleaner is great, but it won't clean everything, I have seen it get rid of 5GB of junk files on one computer before. There is software out there that will get rid of junk, but it takes a little know how. I think once a computer is really infected beyond repair a fresh Windows install is the easiest fix. You can put time into trying to get rid of stuff buried in your registry, but there's a point when trying to save that Windows install just doesn't make sense.