CCleaner is a registry cleaner you should use monthly to keep your computer running efficiently. It scans for junk files, unnecessary registry entries, and unused cookies. (Free, or $25 for professional edition)
Revo Uninstaller Pro scans more deeply for malware and spyware than the standard Windows uninstaller. As it removes files, slowly but thoroughly, it’ll also “uncover any renegade file crumbs left behind.” ($29)
Should I Remove It? helps answer just that. It’s an especially useful tool “if you’re confused about ‘extra’ bundles in the form of adware toolbars.” (Free)
Autoruns cuts boot time by letting you see every program, driver, and extension that starts prior to the booting of your desktop environment. This app is only for knowledgeable users, though, because it won’t tell you what you should and shouldn’t disable. (Free)
Source: CNET.com
