CCleaner

Product: CCleaner 1.41.544
Company: Piriform Ltd.
Website: www.ccleaner.com
Type: Free
Requirements: Windows 2000/XP

CCleaner is a freeware system optimisation and privacy 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. But the best part is that it's fast (normally taking less that a second to run)