I bought Registry Mechanic, and I think it screwed up my computer. It deleted a lot of stuff that allowed spies and viruses to attack my computer. I used to "fix" everything it identified, but one must decide with care what to "fix". Unfortunately, the way it is set up, one must go through a hundred or more "fixes", to decide what to "fix" and what should NOT be "fixed".
Does anyone know anything about Registry Mechanic. It seems to do a lot of things but doesn't tell you what they are. I thought I had a mild improvement in speed but it was far from spectacular.