Want to clean and optimize your PC? You've probably heard of CCleaner, arguably the world's most popular tool for doing the job. It clears out temporary files, cleans the Windows Registry, erases browser histories, and so on. The big news in CCleaner  is a native 64-bit version for use with like editions of Windows.

CCleaner  also sports new icons, various interface improvements, better support for Google Chrome and Internet Explorer 9, and newly added support for programs such as AVG AntiVirus 10.0, Audacity, LogMeIn Hamachi, BitTorrent, and Windows Game Explorer.

I particularly like the way CCleaner intelligently scans for cookies you'd want to keep, like those for Google and Yahoo.

In short, CCleaner is the ultimate system-cleaning tool just got better. It's still free, thankfully, though you can purchase a priority-support license for $25. Developer Piriform is also known for Defraggler and Recuva.

As with any tool of this kind, I strongly recommend making a full system backup and creating a new system-restore point before using it. Better safe than sorry!