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. From Piriform
Cleans all areas of your Computer:
Internet Explorer
Temporary files, history, cookies, Autocomplete form history, index.dat.
Firefox
Temporary files, history, cookies, download history, form history.
Google Chrome
Temporary files, history, cookies, download history, form history.
Opera
Temporary files, history, cookies.
Safari
Temporary files, history, cookies, form history.
Windows
Recycle Bin, Recent Documents, Temporary files and Log files.
Registry Cleaner
Advanced features to remove unused and old registry entries.