CCleaner

Today I'll introduce to you the best registry cleaning software that I've known. Plus it's free~

CCleaner

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! :)

*Update : If you do not know how to use this software you can learn more here:

http://www.ccleaner.com/help/tour