Piriform CCleaner is a free system tool that removes unnecessary or redundant files, fixes errors and optimises software to speed up your PC and protect your privacy. It's one of the most popular PC clean-up tools around, with over a billion downloads.
Everything CCleaner does could be accomplished within Windows itself, but that would take time and a familiarity with many aspects of the Windows OS that many people simply don't have, or have time to learn. CCleaner has a clean, well designed interface and makes it simple to keep on top of the housekeeping any PC needs to keep it running at its best.
CCleaner's key features are:
Registry cleaner - removes unused registry entries, file extensions, ActiveX controls, ClassIDs, progIDs, uninstallers, shared DLLs, fonts, help files, application paths, icons, and invalid shortcuts. We have used this program for years and have never had any issue with important files being deleted, as can happen with other cleaners we've encountered!
Browser cleaner - removes temporary internet files, history, cookies, download history and form history, plus index.dat files from Internet Explorer. This is a convenient way to purge internet history and tracking cookies.
Windows cleaner - that clears the Recycle Bin, recent documents, temporary files, log files, clipboard, DNS cache, error reporting, memory dumps and jump lists.
Third-party program cleaner - cleans non-system apps/programs.
Each element is explained clearly and you can deselect anything you don't want to be cleaned, so you don't accidentally remove anything that you might later need.
The tool we use most often and that's likely to have the greatest impact on system speed is the start-up program manager, which lets you pick and choose which apps start when Windows boots up. As mentioned previously, this is something you can do from within Windows, but for many, the appearance of the list in CCleaner is more user-friendly and less daunting than going through Task Manager, even though it's much more user-friendly in Windows 10.
The free edition of CCleaner doesn't include automatic updates, so you'll be prompted to download the latest version on a regular basis.