Got to know about CCleaner from my friend Mozard. It is a freeware system optimization and privacy tool and has been downloaded over 90 million times.
It removes unused and temporary files from your system thus allowing your PC to run faster. Tried it out and found out that it runs much faster than either Ad-aware and Spybot. I also like that fact that the software includes a registry cleaner (absent in both Ad-aware and Spybot). CCleaner is available in 35 different languages.
Visit the CCleaner website.