If neither of those suggestions solves the problem, you can check your display settings by right clicking on a blank spot in your desktop and choosing settings. I like my icons and screens a little smaller, so mine is set at 1024 x 768 pixels, but there is slider there where you can adjust the screen resolution (and therefore the size) to your preference. Some of the software out there requires a certain resolution, I know some of my photo editing programs are like that and they change the settings for you - unfortunately they don't change them back, so your grandson may have changed the settings without fully realizing what would happen
