CCleaner (Crap Cleaner) 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!
Thanks to g18072020 for the update.