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How to set up dual monitors in Windows 7

There are plenty of reasons to set up a second monitor for your Windows computer: ergonomics, easier scanning of large work spaces, and sharing presentations on a larger screen, to name a few. Here's how to set up your second monitor quickly and simply.

Rob Lightner
Rob Lightner is a tech and gaming writer based in Seattle. He has reviewed games, gadgets, and technical manuals, written copy for space travel gear, and composed horoscopes for cats.
Rob Lightner
3 min read

Watch this: Add a second monitor to your computer

Maybe your neck is reminding you that it prefers a different posture, or maybe you need a desktop that can't be fully displayed in a single monitor. There are many reasons you may want to connect a second monitor to your desktop or laptop Windows 7 machine, and while it's simple, it's not always intuitive. Grab a spare video cable and see how it's done.

  • Make sure you have all the hardware you need -- and that your second monitor is compatible with your computer. A quick glance at the specs sheet should tell you all you need to know, though you may need to double-check your computer's settings. Here are the most important hardware issues to check:
    • Does the monitor work with Windows 7? If it's new, it probably does, but you should still check to make sure.
    • Does the monitor need a fancier video card than you've got? This could be an issue with a laptop and a high-end monitor, but it's well worth checking for a desktop computer as well. Compare the monitor's spec sheet with the information on your computer's video card by selecting Display Adapters in the Device Manager, accessed from the Control Panel. Even if you're unsure, it's safe to proceed, but if things don't work out you may want to contact customer support for the monitor.
    • Do you have the right cable? It may have come with the monitor, though that's not always the case. Most likely your computer and monitor use a VGA or DVI-I interface, so you just need to make sure they've both got the same kind of port. If not, you need to pick up an adapter.
      VGA interface
      VGA interface Evan-Amos
      DVI interface
      DVI interface Evan-Amos
  • Fire up your Control Panel again, choose Hardware and Sound > Display, then choose "Connect to an external display."
    Step 2: Connect to an external display.
    Step 2: Connect to an external display. Screenshot by Rob Lightner/CNET
  • Connect your second monitor. If you don't see a dual-monitor display near the top of your monitor screen, click "Detect" or check to make sure the monitor is connected properly. If you can't find a problem with the connections but the monitor still isn't displaying, it's time to contact customer service.
  • After successfully connecting the second monitor, you can monkey with the resolution or orientation if you like, but you definitely need to choose how the multiple displays will operate. You've got four (really three) options:
    • "Duplicate these displays": This shows the same display on both monitors and can be handy in some situations, especially when you're giving presentations.
    • "Extend these displays": This creates an extended desktop across both monitors. This is great for multitasking or for complex desktop setups, but may take some getting used to before it becomes intuitive.
    • "Show desktop only on 1" or "Show desktop only on 2": If you're using a second monitor to improve your ergonomic situation, this is likely the way to go. Power off one monitor (usually the laptop's primary screen) and focus on the other at a neck-friendly angle.

Step 4: Choose multiple-display options.
Step 4: Choose multiple-display options. Screenshot by Rob Lightner/CNET

That's how it works. Things can get trickier, so be sure to explore the Control Panel for more options. For basic dual-monitor use, this is all you need to know.