On-board graphics adapters will typcially only include a single VGA output.
An on-board video graphics adapter is a video card that is physically built into your motherboard. Even though the video card is a part of your motherboard, an aftermarket video card can still be installed and used on your computer. To use the new video card, you must first disable the on-board video card.
1. Reboot your computer in Safe Mode. There are many different methods utilized by different types of computers to boot into safe mode. To learn the method used by your computer, look at the bottom of the screen immediately after the computer is turned on for the command that allows you to access the boot options. Often, pressing a single key such as “F8” or “F11,” or a combination of keys, such as “ATL” and “F8,” can access the boot options. Once at the boot screen, select “Safe Mode” and press the “Enter” key.
2. Open the Start Menu and right-click on “Computer” or “My Computer,” depending on your version of Windows. Click “Properties” from the right-click menu and then select “Device Manager” from the left side of the System Properties screen. Users running Windows XP or earlier must click the tab labeled “Hardware” and then click “Device Manager.”
3. Locate the “Display Adapters” entry in the Device Manager window and click the “+” to its left.
4. Right click on your on-board display adapter and click “Disable.” Once your display driver is disabled, shut down your computer and install your new display driver.