Content

• To step
• Part 1 of 4: Find out if your computer supports a second display
• Part 2 of 4: Connecting the second display
• Part 4 of 4: Setting display preferences on a Mac
• Tips
• Warnings

This wikiHow shows you how to connect a second monitor to your Windows computer or Mac. By connecting two monitors to your computer, you have twice the screen space to work with.

To step

Part 1 of 4: Find out if your computer supports a second display

1. Know that most laptops support a second display. If you have a laptop with at least one video output (for example an HDMI connection or a VGA connection), you can usually connect a second monitor to the video connection.
   • Some Windows laptops do not support a second display, but all Apple MacBooks do. If you have a Mac laptop, feel free to skip ahead to the steps for connecting your second display.
2. Understand that not all desktop computers support a second display. Depending on the video card and motherboard of your computer, it may not be possible to use two monitors at the same time.
   • If you have an Apple iMac desktop, you can use a second display.
3. Check which video outputs your computer has. Most computers have at least two video outputs, which means that you can usually connect a second display. However, if the two (or more) connections are not next to each other or on top of each other, then they probably do not belong to the same video card and you cannot use them to connect a second display.
   • For example, if you see two horizontal HDMI connections next to or above each other, your computer's video card may support two screens. This also applies to two different types of video outputs (for example, a VGA connection in addition to an HDMI connection).
   • On desktop computers with Windows, these connections are usually located on the back of the computer case.
   • If your desktop computer only has a single video output, then your computer's video card only supports one display at a time. Laptops with a single video output usually support multiple displays.
4. Determine if your motherboard supports two displays. Almost all modern motherboards support multiple monitors, but this is not always the case with older motherboards. You can check if your motherboard supports dual displays by doing the following:
   • Look up the name of your motherboard.
   • Search for the name of your motherboard using a search engine like Google.
   • Choose a search result that shows the characteristics of your motherboard.
   • Look for a feature such as "Multiple Displays", "Multiple Monitors" or "Dual Display".

Part 2 of 4: Connecting the second display

1. Find out what type of video connection your computer has. On the back of your computer case (or monitor if you are using an iMac) you should see several connections, one of which is currently used by your main monitor. Common video connections include:
   • DVI - A wide piece of plastic with numerous small square openings in it.
   • VGA - A piece of colored plastic in the shape of a trapezoid with several holes in it.
   • HDMI - A narrow, flat hexagonal connection. Most modern computers and televisions have such a connection.
   • DisplayPort - Similar to HDMI, but has a flat side on one side and is not symmetrical.
   • Thunderbolt - This connector can be found on the back of most iMac displays. Below the connector is an icon of a lightning bolt. You can connect an adapter to a Thunderbolt connection for all of the above video connections (for example VGA to Thunderbolt).
2. Check which type of connection your second screen has. Your second monitor should have at least one of the above video connections. The second display does not have to have the same type of connection as the first display.
   • For example, you can connect the first display with a DisplayPort cable and the second display with an HDMI cable.
   • In some cases you can connect the second screen wirelessly. For example, to use an iPad as a second display, you can connect it wirelessly to some computers using an app called Air Display.
3. Buy any cables and adapters you don't already have. If you don't have the right cable or adapter for connecting your second display to your computer, you can buy it online or at an electronics store.
   • If you are connecting a second display to an iMac, it is important that you have a Thunderbolt cable or an adapter to be able to connect a display with a different type of connection to the Thunderbolt connector on the back of the first display.
4. Connect the second monitor to the computer. Plug one end of the second display video cable into the back of the computer. Then plug the other end into the second display.
5. Connect the second display to an electrical outlet. Plug the power cable of the second display into a power outlet or power strip with surge protection.
6. Turn on the second display. Press the power button Open Start Open Settings click on System. This is an icon in the form of a monitor in the Settings window.
7. Click on the tab Display. You can find this tab in the top left corner of the window.
8. Scroll down to the "Multiple Displays" section. You can find this at the bottom of the page.
9. Click the drop-down menu under "Multiple monitors". This drop-down menu is under the heading "Multiple monitors". The drop-down menu will now unfold.
10. Choose a display option. From the drop-down menu, click one of the following options depending on your preferences:
    • Expand these displays (recommended) - Uses the second display as an extension of your first display.
    • Duplicate these displays - Show the content of the first screen on the second screen.
    • Display only on 1 - Show the content only on the first screen.
    • Display only on 2 - Show the content only on the second screen.
11. click on To apply. This button can be found under the dropdown menu.
12. click on Keep changes when requested. If you choose to expand your screens, the content will be divided between the first and second screens.

Part 4 of 4: Setting display preferences on a Mac

1. Open the Apple menu click on System Preferences .... This is almost at the top of it Appledrop-down menu.
2. click on Displays. This monitor-shaped icon can be found in the top left corner of the System Preferences window.
3. Click on the tab Ranking. This tab is at the top of the page.
4. Uncheck the box for "Enable video mirroring". If you want to extend the content to the second display, make sure to uncheck the box for "Enable video mirroring".
   • If you want to display the same content on both monitors, you can leave the checkmark in the box for "Enable video mirroring".
5. Change the main display. If you want to use your second monitor as the main screen, you can click the white rectangle at the top of one of the blue monitors and drag it to the second monitor.

Tips

• You can repeat the connection process with multiple monitors, if your computer supports this. That way you can use three or more screens for your desktop.

Warnings

• If the second display has a higher resolution than your main display (or vice versa), then it is best to set the display with the higher resolution so that it has the same resolution as the display with the lower resolution. Failure to do this may result in graphics errors.