Quicksys RegDefrag is no longer an active project. You should try CCleaner instead as it can also clean up the registry.
Quicksys RegDefrag – Free Utility To Defrag Registry
Quacksys is a tool you could use to de-fragment the memory occupied by your registry files. In your system, registry files are written, updated and deleted very often. These registry files are required during the start of each application and while the application is running. If the memory area containing the registry files is fragmented, then your system can slow down considerably. This is when Quicksys comes to the rescue.
This is a freeware application that is small, lightweight and easy to use. This application removes the fragmented spaces and gaps in the registry area. This application works very well with the files and it does not modify any existing registry files. Because of its geat functionality, Quicksys greatly improves the performance and reduces the time required to access your registry files. This has a very easy to use user interface and it provides detailed reports on the actions it performed. This tool is great for people who just want to make their systems run fast as well is computer geeks who want to know about the workings of the registry in-depth.