...and many people use an recommend CCleaner to do what Bill suggests.
Alan
I strongly recommend AGAINST using CCleaner!! I have personal knowledge of instances where CCleaner caused computer crashes -- one case where a complete reformat/reinstall was required to regain use of the computer!!
For anyone not comfortable manually editing the Registry, I maintain CCleaner is a dangerous program! Windows Internet Options offers everything needed to get rid of temp files and internet trash -- why do you need CCleaner???
This utility does a ton more than clearing internet cache and you customize it as to what you want it to remove. I personally know of no one that has hosed there Windows install with CCleaner. It is one of the tools I use on friends PCs when I try to speed them up.