Bartham3,
If hitting 'Print Screen' and then CTRL+V to paste the screen shot into the
document is not working, you can check to make sure the screen shot is
available on the clipboard.
Click the 'Home' tab in the upper left hand corner of the screen. At the
bottom of the tap, where it says 'Clipboard', click the arrow in the lower
right hand corner to open the Clipboard pane. If the screen shot is there,
then Print Screen is working find - click the arrow on the right of the
screen image and choose 'Paste'.
If as suggested in the other answer the 'PrtScrn' key is set to another
function, 'SysRq' (System Request) you can find out more about what that key
is for here
http://en.wikipedia.org/wiki/System_request