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.
What's new in this version:
Version 4.04.4197 added Windows 8.1 Preview support, Internet Explorer 11 cleaning, and Opera 15 cleaning.