Screenshot of what? In a game or just what you have open in Windows? If its during a game theres usually an F key that will do that. If it's in Windows then usually all you have to do is hit the 'Print Screen' Key, then open up 'Paint' in the Start/All Programs/Accessories menu, then hit the 'cntrl+V' keys. It should paste it there. Then you'll want to 'file/save as' a jpg.