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?
CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
Wise Disk Cleaner - Clean junks of Browsers, remove junk and useless files of Windows and Defragment your disk. Wise Disk Cleaner can delete these unnecessary files on your hard disk to free up disk space and make your computer run faster.
BleachBit - When your computer is getting full, BleachBit quickly frees disk space.
AVG PC TuneUp - Peak performance for your PC. Keeps it going for longer. - More Speed Turbo Mode
Recuva - Accidentally deleted an important file? Lost files after a computer crash?