Software: CCleaner

CCleaner is a freeware system optimization, privacy and cleaning tool. It removes unused and temporary files from your system – allowing it to run faster, more efficiently and giving you more HDD space. It also cleans traces of your online activities such as your Internet history. It also cleans registry. It is very easy to use and very fast. Cleaning and optimization of your PC takes minutes not hours.

Homepage: http://www.ccleaner.com