How to add 3 moniters to a pc set up?
Double screen is to use a two-headed output graphics CARDS by two displays. Now almost all the video card is double the output, a VGA a DVI, two DVI or is a DVI a HDMI. Pick a display, only use VGA or DVI (according to different types of display interface and then dual monitor, will be two display from the VGA video card respectively and DVI, if no DVI input, can monitor with DVI turn VGA adapter, will the DVI to VGA video card.
How to make 3 displays actually work depends on your OS.