If your PC has on-board video, you need to carefully check whether it has a second video output or not. The majority of PCs with integrated video do not support two video monitors without the installation of a “real” video card, but if you are lucky enough your PC will have a second video output.

In Figure 4, you can see the rear panel of a typical motherboard with on-board video. As you can see, there is only one video connector (a VGA connector), which is probably already being used by your current video monitor. If your computer is like this then you cannot add a second video monitor directly: you will need to buy an add-on video card. We will talk more about this below.

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Figure 4: Typical motherboard with on-board video. This motherboard (an ECS GeForce6100SM-M) has only one video output.

If you computer is like this one you will need to buy a video card and install it on your computer. With a “real” video card installed you will be able to have up to three video monitors connected to your PC (one on the on-board VGA connector and two to the new video card you will install) – you need to buy a video card that has two video outputs, of course. Please notice that very low-end motherboards don’t have a slot for installing an add-on video card. On current computers this slot is called “x16 PCI Express slot” and you should check whether your computer has this kind of slot or not by taking a look at the motherboard manual or by physically looking for this slot directly on the motherboard. In Figure 5 we show the same motherboard from Figure 4 pointing out the location of the x16 PCI Express slot. Please note that the color of the slot is irrelevant: you can find it in black, blue, yellow, orange, red, etc.

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Figure 5: The x16 PCI Express slot.

In Figure 6, you can see the rear panel of a motherboard with on-board video that has two video outputs. With this motherboard you can install a second video monitor without any extra hardware part. Since your current video monitor will probably be connected to the motherboard VGA connector, you will have the same scenario portrayed in Figure 3, i.e., all you need to do is install your new video monitor to the available DVI connector.

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Figure 6: Motherboard with on-board video and two video outputs (ASUS M2A-VM).