CCleaner is a freeware system optimization, privacy and cleaning tool. It removes unused files from your system – allowing Windows to run faster and freeing up valuable hard disk space. It also cleans traces of your online activities such as your Internet history. Additionally it contains a fully featured registry cleaner. But the best part is that it’s fast (normally taking less than a second to run) and contains NO Spyware or Adware! 🙂
It works simply, efficiently, does the job well, and is free. What more do you want?