What Do You Need to Run Dual Monitors?

By Dan Stone

Multiple monitors can reduce your window management time.
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To run a second monitor, your system's graphics card must support a dual-monitor configuration and have an additional video output port available. The secondary display can work as an extension of the original screen, giving you more screen real estate, or as a duplicate screen. Dual-monitor support is widespread; it is even found on modern laptops and all-in-one computers.

Dual-Monitor Supporting Graphics Card

A quick way to check if a graphics card can support two monitors is to look at the back of the card: if it has more than one screen connector -- including VGA, DVI, Display Port and HDMI -- it can handle a dual-monitor setup. Laptops that feature an outgoing connector also support an external second monitor. A desktop computer without a dual-monitor supporting graphics card can be upgraded with a either PCI Express or PCI graphics card, depending on what expansion slot types the motherboard supports.


Obviously you need to have two monitors to run a dual-monitor setup. The two monitors do not need to be from the same manufacturer, to use the same connection type, to be the same size or display the same resolution: Any two screens should work. The second monitor doesn't have to be a computer monitor either; HDTVs and computers widely support the HDMI connection standard. HDTVs may also carry support for either DVI or VGA as well. Connecting a TV as a secondary monitor works the same way as connecting a traditional monitor.

Cables and Converters

Running dual monitors requires having mutually shared connection types on the monitors and graphics card. If one or both of the monitors doesn't share a common connection format with the graphics card, you can usually attach converters to the card to switch the connection type. For example, you can connect a VGA monitor to a DVI graphics connector by attaching a DVI-to-VGA adapter to the DVI connector. DVI, HDMI and Display Port work with each other, but VGA can only be converted to DVI.

Drivers and Configuration

If you have all your hardware ready, the physical configuration only requires connecting both monitors to their respective computer display sockets and plugging in both monitors to power outlets. The software side requires more work than the hardware side. Before you set up the second screen, download and install your graphics card's latest drivers from the manufacturer's site or through the Windows Update utility. Once the monitors are connected and the drivers installed, you can press "Windows-P" on the keyboard to bring up the dual-screen shortcut menu. Select "Duplicate" to have both monitors display the same screen or select "Expand" to run the second monitor as an extension of the desktop. You can access more advanced configuration options by right-clicking on the desktop and selecting "Screen Resolution" to open a menu of options that enable you to adjust screen resolution and which monitor is on which side.