Whats the laptop and what video card does it have? Usually you have to tell the laptop what port to output on. For instance it's built in LCD display or one of its video ports (hdmi, vga etc.) or both. You can usually do this with a function hotkey (look for pics on the F keys that resemble displays) or by right clicking on the desktop and selecting the appropriate "output to" option (usually under "Graphics Options" or something similar).