Cleanup programs only eliminate bits and pieces left over after you uninstall software, so not that helpful. You've already received good advice about removing the sort of files that usually take a lot of space, like pictures, music and video files. You could also remove software you no longer use, make sure you uninstall it and not just delete it. Might be a good idea to check your downloads, and only keep on the computer stuff you regularly use in game, some of the files I've seen are really huge. Make sure you actually empty the trash bin, otherwise stuff you delete will just be stuck there and not free up your hard drive. Also, make sure to clear your internet browser history, it tends to retain a lot of pictures and stuff that can take an awful lot of space.
