No. Not only is it not necessary, it's a very bad thing to do.
Registry cleaning programs are all snake oil. Cleaning of the
registry isn't needed and is dangerous. Leave the registry alone and
don't use any registry cleaner. Despite what many people think, and
what vendors of registry cleaning software try to convince you of,
having unused registry entries doesn't really hurt you.
The risk of a serious problem caused by a registry cleaner erroneously
removing an entry you need is far greater than any potential benefit
it may have.
Let me point out that neither I nor anyone else who warns against the
use of registry cleaners has ever said that they always cause
problems. If they always caused problems, they would disappear from
the market almost immediately. Many people have used a registry
cleaner and never had a problem with it.
Rather, the problem with a registry cleaner is that it carries with it
the substantial risk of having a problem. And since there is no
benefit to using a registry cleaner, running that risk is a very bad