RegBuster

RegBuster is a lightweight utility designed to help average users clean up broken or corrupt registry keys from the operating system. Ideally, removing broken registry keys has been proven to fix common problems with the OS and speed up the computer.
The program comes with a simple and user-friendly interface that provides a short description regarding the registry key and enables you to select the areas that you prefer to be scanned. The areas that you can scan to identity errors, invalid settings as well as software paths that no longer exist include Control Scan, User Scan, System Software, System Fonts, System Help Files, Shared Libraries, Startup Entries, Installation Strings, Virtual Devices, History and Start Menu, Deep System Scan and MRU Lists. Depending on the options selected and how often you perform maintenance on your computer, you should bear in mind that the analysis process can take up to a few minutes.
Considering the nature of the application, it is highly advisable that you learn more about the registry keys you are about to delete. In the eventuality you erase an important key, then there is a good chance that you cannot use the computer and hence, you need to install Windows from scratch.