Having multiple monitors can greatly increase your productivity and the enjoyment of entertainment such as games. Setting up two monitors is usually easy, because most video cards have two outputs and so using two monitors is simply a matter of hooking them up. Using three is more difficult, however, and requires specific hardware and software settings. Once the third monitor is set up, however, using it is no more difficult than using one or two monitors.
How to Get Three Monitors to Work
Install the video cards that will be used into the computer. If the motherboard of the computer supporting the three displays has a dedicated graphics processing unit (GPU), only one video card will need to be installed. If the motherboard does not have a dedicated GPU, it will be necessary to install a second video card so that three video outputs are available. Also install the driver software for each video card being used.
Connect the monitors that will be used to the video cards. When doing this, keep in mind which monitors are being connected to which video cards. The most powerful video card should be connected to the primary monitor, since this is the monitor which will display content like games and videos and will require the most video processing power. The second and third monitors will mostly display 2-D objects, so the power of the video card they are connected to is less important.
Open the Display Settings options. There should now be three monitors showing in the settings, but if not, press the "Detect" button. The computer will attempt to detect and install drivers for each monitor. Monitors are plug-and-play devices, so there should not be any need to install driver software.
Select "Extend Displays" under the Multiple Displays option to configure the monitors so that they act as an extension of the computer's desktop rather than duplicates. This will allow each display to show different content from the others. It is also possible to not extend the desktop to the second and third monitors, but to leave them open to use by applications.
Arrange the monitors in Display Settings so that they are in the configuration desired. One display should be marked as the "Main Display." For most users, this will be the center display, but this is not a requirement. The arrangement of the displays can be changed by dragging an dropping the displays into different configurations in the Display Settings menu. It is also possible to choose between landscape and portrait orientations.