Set Up Two Computer Monitors

Most computers these days allow you to connect multiple displays. This means you can set up a second monitor as extra desktop space, or switch between your monitor and your TV when you want to watch a movie or play a game. Modern versions of Windows and OS X make setting up a second monitor a fairly straight-forward process, and with an Apple TV and a Mac you don't even need to connect the displays.

Steps

Windows

  1. Determine what connection you currently use. Look at the back of your computer where the monitor is currently plugged in. If the monitor plug is connected vertically towards the top of the computer, and is surrounded by various other connection ports like USB, Ethernet, speakers, and others, it is connected to the motherboard. If it is connected horizontally below the motherboard inputs, it is plugged into the graphics card.
    • Both monitors must be attached to the same graphics card. If your monitor is currently plugged into the motherboard, you will need to unplug it and plug it into the graphics card. If you don't have a graphics card, you will need to install one before setting up dual monitors.
  2. Check your available ports. Look at the ports available on your graphics card. These will determine the ways that you can connect your monitors, and will let you know whether or not you will need any adapters.
    • HDMI - This is the new standard in display connectivity, and can be found on virtually all computers built in the last five years. It looks like an elongated USB port. HDMI can transfer image as well as sound, and results in the best picture quality.
    • DVI-I/DVI-D - DVI (Digital Video Interface) has long been the standard way to connect a flat-panel monitor to a computer. DVI-I has a "+" connector on the right side, while DVI-D has a "-" connector. Both can be used to connect a DVI monitor to the computer, but only DVI-I can accept a VGA-to-DVI adapter. If a card has two DVI ports, generally only one of them will be DVI-I.[1]
    • VGA - VGA is an analog output, and was most common in the CRT-era of computer displays. It has largely been phased out of any recent hardware, but you may encounter it with older computers or CRT monitors.
    • DisplayPort - This is a digital connection, similar to HDMI. DisplayPort is necessary for 4K displays, and is not as common as HDMI.
  3. Power down your computer. Your monitors will be easiest to configure if you power down your computer first. This isn't necessary for HDMI or DisplayPort connections.
  4. Attach the second monitor. Attach your second monitor to your graphics card. Make sure that your primary monitor is connected to the best video output. For example, if you have an HDMI monitor and a VGA monitor, you'll probably want your primary monitor to connect via HDMI.
    • If you are using VGA or DVI, make sure to secure the cable with the built-in screws.
  5. Setup the monitor in Windows. Power on your computer and boot up Windows. Windows will automatically detect virtually any monitor. Right-click the desktop and select Screen resolution. If you are using Windows XP, right-click the desktop, select Properties, and then click the Settings tab.
    • Use the "Multiple displays" drop-down menu to indicate whether you want to extend your desktop, duplicate your display, or keep the desktop on a single display.
    • Extending your desktop allows you to move windows icons, and other objects between your screens.
  6. Quickly switch between screen types. You can quickly cycle through the available display types by opening the Project menu. This is only available in Windows 7 and 8.
    • Pressing the Windows key + P opens the menu and lets you quickly select "Primary Only", "Duplicate", "Extend", and "Secondary Only".

Mac OS X

  1. Check your available ports. In order to attach another monitor, your Mac or MacBook must have a port to attach it to. You can purchase adapters that allow you to connect more modern displays to older computer, and vice versa.
    • HDMI - This is the new standard in display connectivity, and can be found on virtually all computers built in the last five years. It looks like an elongated USB port. HDMI can transfer image as well as sound, and results in the best picture quality.
    • DVI/Mini-DVI - DVI (Digital Video Interface) has long been the standard way to connect a flat-panel monitor to a computer. Mini-DVI is an Apple-specific connection that acts like DVI but in a smaller form.
    • VGA - VGA is an analog output, and was most common in the CRT-era of computer displays. It has largely been phased out of any recent hardware, but you may encounter it with older computers or CRT monitors.
    • DisplayPort/Thunderbolt - Macs have been using DisplayPort technology for much longer than most PCs, and the new Thunderbolt connector is an evolution of that. DisplayPort monitors can plug into both DisplayPort and Thunderbolt outputs, while a Thunderbolt monitor can only work on a Thunderbolt output.[2]
    • Adapters - There are several adapters available for users that need to connect a monitor to a different port on their mac. Some of the more useful adapters include: Thunderbolt-to-HDMI, VGA-to-DVI, Mini-DVI-to-DVI, and DVI-to-HDMI.
  2. Connect the monitor. Power down your Mac first if you are connecting a VGA or DVI monitor. Otherwise, you can just plug it in. If you are using VGA or DVI, make sure to secure the cable with the built-in screws.
  3. Configure the new monitor. Click the Apple menu and select System Preferences. Choose "Displays". Click the "Arrangement" tab. Adjust the screen placement so that your mouse cursor flows naturally between monitors.
    • By default, OS X will extend the desktop to the second display. You can check the "Mirror Displays" box to duplicate your display.
  4. Select a resolution. OS X will attempt to determine a resolution that works on both displays. You can set the resolution yourself, but the image may looks stretched or blurry if you don't select the recommended resolution.

Mac OS X and Apple TV

  1. Configure AirPlay on your Apple TV. This will allow you to use your HDTV as a second display without having to connect it to your computer. Using Apple TV as a second display requires Mountain Lion or later, and your computer must be connected to the same network as the Apple TV.
    • If you have Mountain Lion, you can only mirror your display. If you have Mavericks, you can use the second display as an extension of your desktop.
    • See this guide for details on setting up your Apple TV.
  2. Click the AirPlay menu. When you are connected to the same network as a properly configured Apple TV, the AirPlay menu will appear in your Mac's menu bar. Click it and select your Apple TV from the devices list.
  3. Rearrange your displays. Click the Apple menu and select System Preferences. Choose "Displays". Click the "Arrangement" tab. Adjust the screen placement so that your mouse cursor flows naturally between monitors.
    • If you are using Mavericks, you can check the "Mirror Displays" box to duplicate your display.
  4. Use Spaces to organize your windows on each screen. Use-Spaces-on-Mac-OS-X allow you to keep your different windows organized as you multitask. Each open window is assigned to a Space. This allows you to keep your windows organized for specific tasks.
    • Windows will not span displays by default. You will need to disable this in the Mission Control section of the System Preferences window. Uncheck the "Displays have separate spaces" box.
    • You can assign apps to specific spaces by right-clicking the icon in your Dock. Select Options and then choose the display you want to assign it to.

Tips

  • Most entry-level PC's do not have dual-monitor capable graphics cards, but have integrated cards instead. You will most likely need a dedicated graphics card for this feature.

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Sources and Citations