The Windows registry is a very complicated filing system that Windows uses to store all the important preference and settings files for all your software and hardware programs.  The registry is very delicate, and it’s NOT recommended that you attempt to fix it or tinker with it by hand.  That’s unless you’re very knowledgable and know precisely what you’re doing.  For the rest of us, there are special programs called registry cleaners that will automatically scan the registry and remove all the bad files and folders.  The best Vista registry cleaner is RegCure.  Published by ParetoLogic software, RegCure will defnitely get rid of all the invalid registry files and keys.