Comodo System Cleaner Portable bests the crowded Registry cleaner field on several fronts: it's completely portable; its SafeDelete feature effectively prevents you from deleting the wrong files, and makes it easy to restore them if you do; it actually improves your system's performance; and it's free, unlike the many others that will scan your system but make you pay for the software to clean it. It effectively cleans files, the disk Registry, and privacy threats. It removes corrupt and unnecessary Registry entries, deletes duplicate files and needless archives, and removes digital traces from browsers and other programs. It actually boosts PC speed by cleaning out the junk that piles up over time. It even offers useful extras, such as its Windows Customization Tool for tweaking your system.
The program downloads as a Zip file, but it's accessible immediately after extraction, with no need to install it. That's the key to its portability: you can install it on a flash drive and carry it between PCs, and it will work each time. It has the typically helpful and colorful interface of such utilities, with nice touches like friendly nag screens that remind you to check things out before making permanent changes (which its easy backup can restore, if needed). Comodo compares its SafeDelete to a "smart" vacuum cleaner that cleans deeply without touching your important possessions. Live technical support and Web forums are rare and welcome extras for freeware.
Comodo System Cleaner Portable is ready for Windows 7.