Do redgestery cleaners do anything

I have used regestry mechanic alot in the past and have not yet installed one on a new version of windows 7. Do regestery cleaners realy work and is it nessesary to install one to keep your P.C. HEALTHY OR IS IT A MASS SCAM?

Well, it can go either way. Registry cleaners will, on average (based on experience), have anywhere from 75-500 entries that are eligible for removing. Computers these days can have 1million+ entries within the Registry, so a few hundred, even a few thousand, isn't going to give you the increase in seek time as you'd anticipate with running a cleaner of some kind.

Now, if one of those Registry values turn out to be "important" and actually needs to be cleaned/repaired, then yes, absolutely the Registry cleaner is beneficial. All in all, if you already have a software and the scan only takes 5-10 minutes, running it once every few months wouldn't hurt.