Welcome to the forum elcid! Personally I've never liked registry cleaners, I don't trust them. I think many of them have done more harm than good. Generally speaking, I'd steer clear of all those miricle registry cleaners.
There are some who use and like ccleaner, and there are a couple different defraggers like Defraggler that are mentioned favorably by several here.
One thing I believe is helpful is a good uninstaller. Nibiru put me onto "My Uninstaller Pro" and I like it. It does a good job of not leaving garbage in the registry when you uninstall programs.
Here's a thread that lists a lot of W7 member's "Favorite Utilities".....
Favorite Utilities?