TweakNow Registry Cleaner
Remember the day when you first boot up your newly installed Windows PC. Everything was so fast then. Now after a few months / years, it is as slow as a turtle. The lag that you had experienced can be blamed on various causes, the registry is one of the most common one.
A registry contains information that controls how your Windows appears and how it behaves. It's the heart of a Windows system. Sometimes when you remove applications from your PC, it doesn't remove all of it's content and the remaining data will clutter your registry. Simply put it, this obsolete entries will make your registry file bigger and Windows will have trouble to load, search, and read data from registry.
So to wipe out those pesky obsolete entries, I recommend you this freeware, Tweaknow RegCleaner. There are many registry cleaners available, but it's features really stands out above the rest: -
Download it from http://tweaknow.com/RegCleaner.html