Hello.

Be certain that the VGA cable (connected from the projector to the laptop) is snug.

If you look at the "F" keys (top row of your keyboard), you should either see "CRT/LCD" or see a symbol of a screen. That's the function key you press, along with the Fn key (actually, hold the Fn key then press that "F" key). The first press shows one screen, the 2 press the other screen and the 3rd press both screens.

Hope this helps.