1)   Auslogics Registry Defrag 6.2.0
Auslogics Registry Defrag can significantly speed up your computer by helping you to defragment the Registry, remove gaps and make it contiguous, smaller and faster to access. The program is free of charge.

 2)   WinASO Registry Optimizer 4.0.5
Speed-up your System. WinASO Registry Optimizer repairs Windows registry problems with a few mouse clicks. Scanning and clearing the history of the use of programs and applications in your system

 3)   Free Registry Defrag 2.35
During the normal operation of a Windows system, many holes and fragments are left in Windows registry. Our Free Registry Defrag optimizes your registry by removing gaps and wasted space, thus improves the whole system performance.

 4)   Registry Defragmenter 8.9
Tired of slow Windows load? Easily eliminate slow startup, shutdown speed and computer crashes. Keep your registry as compact as possible and improve your computer performance.