If you're a fan of programs which claim to be able to speed up/optimize/clean up your Windows installation, then you'll like 360amigo. It's quick, friendly, and easy to use. And while the paid-for version costs around $20 a year, there's also a freebie version which has loads of useful features.
Running it on my test XP system, it found 353 unnecessary registry entries, and 2007 unnecessary temporary files, all of which it deleted. There's an option to create a system restore point before anything gets deleted, which is definitely a good idea before running a program such as this for the first time on your PC. A full, recent backup would be even more sensible, and is definitely recommended.
Having said that, 360amigo performed flawlessly for me when I tested it in a Windows XP environment under VMware Player.
If you want to try it for yourself, see www.360amigo.com. The download is around 3 MB, and it runs on Windows XP, Vista and 7. Including 64-bit.
Got a Hot Find that you want to tell me about? See http://www.techsupportalert.com/content/submit-product-review.htm.