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)   RegVac Registry Cleaner 5.01.03
RegVac - 6 cleaners, 3 editors, and 7 tools that get the registry sparkling clean, speed up your computer, avoid computer crashes, and repair Windows and applications. Stronger cleaning power than other registry cleaners. Forever Free updates.

 3)   Registry Defragmentation 9.2.1.20
Registry Defragmentation is a small utility that does gigantic improvements in computer performance. This application physically defragments the Windows registry file to give it the proper linear structure.

 4)   Advanced Registry Doctor Pro 9.3.6.2
Fix your registry & improve your PC's performance! Is your system becoming increasingly slow and unstable? If so, you need a professional registry cleaner and repair tool. Advanced Registry Doctor is the answer!

 5)   APC Clean Up Speed Up Utilities 3.5.4.1243231
Clean Up Speed Up Utilities (Glary Utilities) is a collection of system tools and utilities to fix, speed up, maintain and protect your PC.It allows you to clean common system junk files, as well as invalid registry entries and Internet traces.