Instructions
Launch "Defense of the Ancients" and start a play session.
Progress through the play session until you reach a point that you want to record by taking a screen shot.
Press the "Prt Scr" button on your keyboard. This will take and save a screenshot.
Close "Defense of the Ancients" and open the "Warcraft 3" directory. You will find the screen shot you took in the "Screenshots" folder.