So I have two screens (one a TV and a normal computer screen) and I don't know how to enable the second screen (tv). My primary screen (pc) is plugged into my video card (NVIDIA GeForce GTX 660), but the card only has one HDMI output. So I plugged my secondary screen into the output of the motherboard (Intel Core i5-4570 CPU @ 3.20 GHz) but I don't know how to enable this output because it doesn't show up in the device manager.