Understanding multiple monitors

Whether you're connecting your mobile PC to a wall-mounted plasma display in a conference room or to the monitor that you use with your desktop computer, it's easy to enhance your video capability with additional displays.

When you connect an additional monitor, Windows automatically detects it and applies the video settings best suited to the monitor's display. You no longer need to use Control Panel every time that you want to apply new display settings.

When you disconnect the additional monitor, the original display settings are restored to your primary display. In addition, all open files and program windows are moved to the primary display. The next time that you connect the same monitor, Windows automatically applies the display settings that you used the last time that you connected this monitor.

Change your display settings

To select different display settings at any time, open Display Settings in Control Panel.

Open Display Settings by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Appearance and Personalization, clicking Personalization, and then clicking Display Settings.

Choose the appearance of additional displays

After you connect an additional monitor, you can use the New Display Detected dialog box to indicate how you want your desktop to appear on the monitor's display.

You can choose to mirror, or duplicate, your desktop on all displays. A mirrored desktop—the default display option—is useful if you plan to use your mobile PC to give a presentation on a projector or a fixed display in a conference room, such as a wall-mounted plasma display or TV-type monitor.

Example of a desktop mirrored on two displays
Mirrored desktop display

When you want to increase your desktop area, you can extend your desktop across all displays, so that you can move program windows back and forth between the different displays. For example, you can use Microsoft Office OneNote to take notes on your mobile PC while presenting information to colleagues on an external display that everyone can see.

Example of a desktop extended across two displays
Extended desktop display

You can also show your desktop only on the external display. This option is useful when you play a DVD on a mobile PC that supports full-screen video playback on a single display. You can also save battery power by turning off the mobile PC display and using only the external display.

Example of a desktop shown only on an external display
External desktop only display


  • Windows can automatically detect only one additional display. If you connect two or more monitors to your mobile PC, you must manually designate the primary display, arrange your desktop, and apply display settings such as screen resolution and color depth. The next time you connect any of these monitors, Windows automatically identifies the primary display and applies the settings that you previously specified for each additional display.

How Windows manages multiple displays

Windows periodically checks for additional displays. If additional displays are detected when you connect to an external monitor or dock your mobile PC at your desk, the New Display Detected dialog box appears. Windows also automatically collects basic information about the video capabilities of the additional displays, including screen size, resolution, and color depth.

After gathering information from your primary and additional displays, Windows applies the video settings that are best suited to each display.

Most display types can be detected. If a particular display can't be identified, you can manually open the New Display Detected dialog box in one of the following ways:

  • Open Windows Mobility Center by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Mobile PC, and then clicking Windows Mobility Center.

    Then, on the External Display tile, click Connect display.

  • Use the correct keyboard shortcut on your mobile PC. The keyboard shortcut used to activate an external display varies depending on the mobile PC manufacturer. To learn more, check the information that came with your mobile PC or go to the manufacturer’s website.