|If the drivers for your video adapter supports two displays - two computer monitors, or a monitor and a TV out or HDMI or HDTV output, there will always be two displays in Display Properties - Settings. Just unplug the video cable of the monitor or the other connection cable (Svideo , HDTV, HDMI etc.) you no longer want to use, when the computer is not running. Windows will disable the second display in Display Properties automatically if nothing is detected connected to the second connection while booting Windows - if you hold your cursor over the displays there, one will reveal its disabled. |
(If you connect two things again, usually Windows will not enable the second display automatically - in that case you have to RIGHT click on the disabled display in Display Properties and enable it or similar.)
If your computer supports connecting two computer monitors to the same video adapter, preferably, the monitor you want to use should be connected to the primary video port of the adapter, not the secondary one. Windows usually designates whatever you have a single computer monitor connected to as the Primary adapter in Windows in Display Properties, but that isn't necessarily the video adapter's Primary port. See the manual for the brand name system if it's built in, or the manual for the video card in a mboard slot if it wasn't built into the mboard, to determine which computer monitor port is the Primary one. .