CCleaner is developed by Piriform and was initially released in 2003. It is a program that cleans up all unwanted/unused material from your computer which can help speed up performance.
Many programs accumulate unused files (for example internet history, tracking cookies and 'recent files') which can all slow down your computer.
CCleaner cleans up the unnecessary files of many softwares. This includes cleaning and correcting the registry. CCleaner also backs up your registry in case an important component is removed.
This software can also be used to uninstall programs or to disable start-up programs, further speeding up your computer.