Whether you want to show your desktop during a meeting or presentation, or simply want to increase your desktop area, you aren't obligated to use the same display settings for each monitor that you connect. After you connect an
additional monitor, it's easy to adjust the display settings.
Windows can automatically detect only one additional display. If you connect two or more monitors, you must manually designate the primary display, arrange your desktop, and apply display settings, such as screen resolution and color depth. Then, the next time that you connect these monitors, Windows automatically identifies the primary display and applies the settings that you previously specified for each additional display.
Open Display Settings by clicking the Start button , clicking Control Panel, clicking Appearance and Personalization, clicking Personalization, and then clicking Display Settings.
To designate the primary display, on the Monitor tab, click the icon that corresponds to the monitor that you want to designate as the primary display, and then select the This is my main monitor check box.
Select the screen resolution and color quality for each monitor that you're using.