Windows Vista Disk Cleanup wizard is really not all that bad, but I did find a small problem with it… It doesn’t fully empty your temp folder. It only allows you to delete temporary files that haven’t been modified in a week, as you can see in the screenshot.
If you’ve recently done a lot of editing or something that generates large temporary files, you may want to manually clean up. Just type in %TEMP% into the start menu search box, and hit enter. You’ll immediate be taken to the temporary files folder, where you can delete whatever you feel like.