CCleaner is famous cleaning software developed by Piriform. CCleaner helps us to clean the junk files present in the computer. It also cleans the history, temporary Internet files and other hidden data and protects our privacy. It is very efficient in cleaning the junk files and temporary Internet files and is commonly used by those who use Internet. This software also has the function of cleaning unwanted registry files and the unwanted shortcut references and missing dll references from the registry. CCleaner is very efficient in all these functions and thus by cleaning unwanted files and registry, the computer performance is improved. CCleaner can also be used as an uninstaller, it also contains an option to remove items from windows startup, all these features help in increasing the overall performance of the system and maintain sufficient privacy in the computer by deleting history and temporary Internet files. Using CCleaner will not affect the system files and if a registry cleaning is to be performed we can make a backup if we want.