How to Hook Up Dual Monitors Using VGA Cables

by David Weedmark

Even if you have only a single VGA port on your computer, you can easily add a second monitor to your PC using a VGA splitter. In the past, VGA splitters were large bulky boxes requiring a separate power supply. Today, you can get a VGA splitter that is powered by the computer itself through a USB port. All you need is the splitter and a VGA cable for each monitor. When you connect the monitors, Windows will automatically detect them and you can use the screen resolution settings window to position the monitors. You can position monitors so they give you a side-by-side view of the computer screen, one above the other or mirror them so they show the same view.

Installing a USB VGA Splitter

Turn off the computer and its monitor. Disconnect the monitor from the computer's VGA port.

Connect both monitors to the end of the VGA splitter cable that has two female connectors.

Connect the male end of the VGA splitter to the VGA port on the computer.

Connect the USB cable of the VGA splitter into a USB port directly on your computer. Note that a USB port on a keyboard or other accessory may not be adequate, as the USB cable supplies power to the splitter.


Turn on the computer and both monitors. Click the Windows Start button and select the "Control Panel." Select "Adjust Screen Resolution" in the Appearance and Personalization section of the Control Panel.

Click the "Detect" button if Windows shows an image only one one monitor. Two icons should appear in the Screen Resolution window when both monitors have been successfully detected. One monitor is identified as "1" and the other as "2" in the icons.

Click "Identify" to determine which icon represents which monitor if you are uncertain which is which.

Click the "Multiple Displays" menu and select "Extend These Displays" to make both monitors one extended view of your computer. Select "Duplicate These Displays" to have both monitors show the same single view of your computer.

Drag the icons representing the monitors to change their positions if you selected the extended display option. For example, you can move a monitor to the left or right of the other.

Change the resolution or orientation of either monitor by first selecting the monitor in the "Display" menu, and then selecting your desired settings in the "Resolution" or "Orientation" menu.


  • Replacing your computer's video card with a video card with two VGA ports eliminates the need to use a VGA splitter.

Items you will need

  • USB VGA splitter
  • 2 VGA cables

Photo Credits

  • Comstock Images/Comstock/Getty Images