When it comes to system junk files cleaning software on Windows, many users will recommend Piriform's CCleaner first - which has almost become one of must-have tools for any computer. CCleaner is free, small, has multi-language interface, and runs fast. Especially, it is fairly stable and safe to use, even the novice computer user won't encounter a problem due to misuse. CCleaner for Mac is a free system useless files cleaner, system optimizer and privacy protector specially designed and developed for Mac users. It is actually the Mac version of CCleaner.

It is necessary to do defragmentation to hard drive at fixed period, in order to maintain its read/write speed. Windows has built in an "Optimize Drives" already at an earlier time, but its defragment speed and effect are really difficult to satisfy users. So many more powerful third-party disk defragmenters get their markets.

Recuva is a deleted files recovery tool under Windows platform made by Piriform. It can be used to restore any format of files deleted by mistake from hard drive, USB flash drive, flash memory card (such as SD card, MMC, etc.).

CCleaner is a user friendly system junk files cleaning application (has both system optimization and privacy protection functions), it can clear most of the useless files and garbage information from your system, makes your Windows run faster, higher efficiency, and release more disk space.