RegCool - RegCool is an advanced registry editor.
CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
Registrar Registry Manager - Advanced Registry Manager for Windows
Glary Utilities - The No. 1 Free, Powerful and All-in-one utility for cleaning your PC
Regedit - The Microsoft Registry Editor (regedit.
BleachBit - When your computer is getting full, BleachBit quickly frees disk space.