How to Connect a Projector to a Computer

Project from your Windows PC

What to Know

  • An HDMI or VGA cable works for most setups.
  • Chromecast is another option.
  • A wireless connection via Miracast is possible in some cases.

This article explains how to connect a Windows desktop or laptop to a projector using a wired or wireless method, depending on your situation.

Attach an HDMI Cable

This setup is similar to using dual monitors on Windows because you're using a cable to add a second display to your laptop or desktop.

  1. Power down both the projector and the computer.

    This step isn't necessary, but it's best to connect the cable (coming up in Step 2) before they're running to avoid issues with one device not recognizing the other,

  2. Connect the two with an HDMI cable, which is best because it carries audio, too. But if you don’t need audio (or have a separate audio cable) or HDMI isn’t an option, most projectors and computers also have a VGA or DVI port.

    HDMI port on back of Dell XPS desktop computer
    Desktop with HDMI port.


    The cable you need depends on the ports that are available on both devices. If there are different ports (e.g., HDMI on one but VGA on the other), you'll need an adapter. Amazon has lots of adapters for various configurations, such as HDMI to VGA.

    If you’re in a school or office, there’s a good chance there’s already a cable coming from the projector that you can plug into your computer.

  3. Power on both devices.

  4. On your computer, press WIN+P and then select an option:

    extend screen projection option in Windows 10
    • PC screen only (called Computer only in Windows 7) essentially disconnects your screen from the projector—don’t choose this one.
    • Duplicate will do just that: show the same thing as what’s on the computer
    • Extend turns the projector into a second screen, letting you drag items between the two.
    • Second screen only (called Projector only in Windows 7) shows everything on the projector and nothing on your computer.

If this doesn’t work or Windows can’t find the projector, press the Input button on the projector to search for the computer.

Plug In a Chromecast or Roku

In many cases, someone wants to connect a computer and projector for a particular reason, like watching a movie or showing pictures or a presentation, not necessarily to project the whole computer screen. If this is your situation, a streaming media device like Chromecast or Roku is easy to set up and works if the projector supports HDMI.

  1. Turn on the projector and plug the Chromecast into an available HDMI port. If there's a USB port on the projector, too, or a plug nearby, you'll need to use that, too, if the device requires it for power.

  2. Set up the device if you need to.

    We have instructions on setting up a Chromecast and setting up a Roku if you need guidance.

  3. Send to the projector whatever it is you want to show up on the screen. How you do this depends on the device you're using and what you're projecting.

    For example, if you've got a Chromecast and want to project your computer screen, it's as easy as using Chrome's built-in Cast feature—it lets you show a specific tab, your whole screen, or a file on the projector.

    Cast tab options in Chrome
    Cast tab options in Chrome for Chromecast.

    If your computer supports Miracast (more on that below), you can use screen mirroring on a Roku.

Miracast Could Be an Option

Some devices support wireless connections via Miracast, which is much more convenient than a cable for ceiling-mounted projectors. However, it's likely not supported by as many projectors as Chromecast.

Check this list of Miracast devices to see if both your PC and the projector are supported. If you’re still not sure, walk through these steps to see if it works.

These are general directions that should point you in the right direction, but they might not make perfect sense with your specific projector.

  1. Use the Input or LAN button on the projector or its remote to select Screen Mirroring

  2. From the menu on the projector, go to Network > Screen Mirroring > ON.

  3. Press WIN+K on your computer and then choose the projector from the list to project your screen.

  • Why is the computer not connecting to the projector?

    Usually, this problem is caused by a faulty cable connection. Check to make sure all of the cables between the computer and projector are plugged in securely. If you notice any damaged cables, swap them out for new ones.

  • How do you connect a phone to a projector?

    If you have an Android phone, the easiest way to connect to a projector is with a Chromecast streaming adapter. It costs about $35 and uses the HDMI port on your projector. iPhone owners can use a Digital AV or VGA adapter to connect their phones to their projectors.

  • How do you hang a projector screen?

    Pick a good location for the screen and projector, then install the wall or ceiling mount. Get someone to help you lift up the screen and screw it into the mount. Don't overtighten the screws. Attach the rope that came with it so you can raise or lower the screen, then make sure the projector is aligned correctly with the screen.

  • What does contrast ratio mean in a projector?

    Contrast ratio is the amount of black and white that's present in an image. Something with high contrast ratio depicts whiter whites and blacker blacks. A low contrast ratio can make images look washed out.

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