CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
DLL-files.com - Find missing DLL (dynamically linked library) files for your Windows computer.
BleachBit - When your computer is getting full, BleachBit quickly frees disk space.
DllHub.com - Search all of your missing dll files at dll-hub.com . Corrupt dll or dll's with error can be fixed by downloading correct dll's. These dll files are available for free here.
AVG PC TuneUp - Peak performance for your PC. Keeps it going for longer. - More Speed Turbo Mode
WikiDll - Download DLL files and fix missing DLL errors.