You need to have software on your computer that will allow you to do a screen capture by pressing that button on your keyboard "print screen". You can find software for free to use this feature. You can find more information here:
. http://download.cnet.com/1770-20_4-0.html?query=print+screen+software&searchtype=downloads&filter=licenseName=Free|platform=Windows,Webware&filterName=licenseName=Free|platform=Windows,Webware&tag=ltcol