X-Setup Pro is a so-called "hacker" or "tweaker" program. It allows you to change settings that are normally hidden deeply in some configuration-files like the registry fast and easily. It offers several advantages, making it the "ultimate tool for black belt system tuning". It's runs on any Windows version, is clutter-free, easy to use, extensible, powerful, covers any aspect of your computer and has more configuration options than any other tweaker.
Get it here.