Freeware registry cleaners

I have a couple of registry cleaners that I run whenever I install or uninstall a program—Windows generally mucks up the registry with either action. MakeUseOf.com has a post on the top freeware registry cleaners, so I downloaded the free version of the top-ranked package and just ran it. It found and fixed 877 registry errors that the other programs apparently missed. (It does do a full registry backup if you want before starting the fix process, and it does a checkpoint before doing the fix.)