Wincleaner is the first one I found when looking around. From what I've just read, it basically deletes temp files and "cleans" your registry. It sounds similar to most of the "speed up your PC" junk that's out there. Probably about half of the reinstalls I've done for clients over the years have been a direct result of them trying out registry boosters, and one click PC optimizers. Pretty much everything you need to maintain your PC can be had for free, its just a matter of going down the line doing regular maintenance. Once a week, run the built in Windows disk clean up. When that's done, run CCleaner. If you're not especially savvy, just do the clean up portion, leave the registry alone. Next, grab Defraggler from the same place and use that to defrag every couple of weeks. Assuming you still have an old fashioned platter drive that is, do NOT defrag an SSD. Keep on top of Windows updates, as well as updates for other software you run. Java, skype, flash etc. If you download each of those programs, just place the shortcuts on the right edge of your screen in the order I gave you, top to bottom. Then, once a week, just run down the list. Start at the top, and work your way down.