CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
Tech Tool Store - Tech tool store is an IT professional application which contains more than 600 free technician tools packed in a simple, fully featured interface.
BleachBit - When your computer is getting full, BleachBit quickly frees disk space.
Tweaking.com - Windows Repair - An all-in-one repair tool to help fix a large majority of known Windows problems including registry errors and file permissions as well as issues with Internet Explorer, Windows Update, Windows Firewall and more.
AVG PC TuneUp - Peak performance for your PC. Keeps it going for longer. - More Speed Turbo Mode
Tron Script - Tron is a glorified collection of batch files that automate the process of cleaning up Windows systems.