ad-aware from lavasoft is pretty good. although it had a tendency to delete certain system files, it's still good and easy to use. i'm not sure but i think the current version is a little more selective about the files that it detects. http://www.lavasoftusa.com/
You don't need a program for that. Just go into Tools, Internet options and clear history. Then go to start, programs, accesories, the disc clean up and make sure to delete your temporary internet files.