Reg Organizer is a Windows registry optimizer and junk file cleaner. I love its interface, and the manner in which all the tools are neatly arranged. You can perform cleanup of invalid keys, optimization of Windows settings, etc. This application can defragment registry hives to improve its speed of access. It is also an alternative to the regedit tool in Windows; important sections of the registry are carefully classified and arranged, so that anyone can understand them.