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.
SDelete - Securely overwrite your sensitive files and cleanse your free space of previously deleted files using this DoD-compliant secure delete program.
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.
CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
Tron Script - Tron is a glorified collection of batch files that automate the process of cleaning up Windows systems.
Clean Master - Some users swear by it, some call it a glorified snake oil that does more harm than good. That can be said about any snake oil, but what specific brand of snake oil can boast almost a billion downloads around the world?