Graphics files can tie up a lot of disk space.
You'll likely have to delete many Word document files to free up the same amount of space that you would free up by deleting one graphics file. Sometimes, computers come installed with clipart packages. If yours does and you don't use it, removing it will free up a lot of space quickly. If you want to delete whole applications, use an uninstallation program so you don't accidentally delete something crucial to the everyday running of your system. If you're not sure whether you'll need some of the items on your hard drive again, you might want to consider backing it up onto a Zip drive or some other removable storage medium.