Win Toolkit - BUGS: Do not post bugs in the comments.
CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
Ultimate Windows Tweaker - Ultimate Windows Tweaker is a freeware Tweak UI Utility for tweaking and optimizing Windows.
Glary Utilities - The No. 1 Free, Powerful and All-in-one utility for cleaning your PC
NTLite - The Ultimate Windows Customization Tool
BleachBit - When your computer is getting full, BleachBit quickly frees disk space.