It differs from computer to computer.
I personally use Photoshop to save my screen shots, since they are essentially saved to the clipboard.
i believe if you hit the Printscreen button in combination with Alt, controll, or Shift, each produces a slightly different effect.
have you tried looking on a non UR related web forum for info about printscreen?
In your keyboard there is a print screen button. Then open from your start menu Paint and then right click and select paste. Save the picture in the format of your choice. Hope this helps.
Click PRT SCR than paste it at paint or microsoft word or something