A way to "take a picture" of you monitor is by simply using the key board.

Step 1: Taking a Picture.

To take a picture of the whole screen press the "Print Screen" button.
If you want to take a picture of a program that is not filling up the whole screen; make the window you want to take a picture of, the active window the press alt and "Print Screen" at the same time.

(Note: You do not have to use the on screen keyboard to preform the action of taking a picture.)

Step 2: Seeing the Picture

To see the picture open up a simple drawing program such as MS Paint. Go to Edit --> Paste (or Ctrl+v) and there is the picture ready to be saved, drawn on, or anything you can think of.