When using Windows 8.1, from time to time you may need to change the screen resolution. For instance, you might have connected a new monitor to your desktop computer, and need to change the resolution to match it. Or you might have plugged a projector into your laptop computer, and need to adjust the resolution to better display your screen on the projector. Windows 8.1 offers two ways to change the resolution, one through the PC Settings app, and one through the Desktop Control Panel.
To change your resolution through the PC Settings app, launch PC Settings by pressing WINDOWS+C to summon the Charms Bar, clicking on the Settings charm, and then clicking on the PC Settings link. Alternately you can click on the PC Settings tile on your Start Screen.
Once PC Settings launches, click or tap on the PC & Devices category in the left-hand pane. When the PC & Settings category expands, click or tap on the Display category. A slider in the right-hand pane will display your screen resolution, and you can drag it left or right to move to a lower resolution or a higher resolution. Note that all displays may not be physically capable of displaying all available resolutions.
To change your resolution from the Desktop, go to the Desktop by hitting the WINDOWS+D keys simultaneously or clicking/tapping on the Start Screen’s Desktop tile. Once the Desktop appears, right-click on a blank spot on the Desktop and select Screen Resolution from the menu. This will bring up the Screen Resolution control panel. You can change the resolution through the Resolution dropdown menu. Note that all displays may not be physically capable of displaying all available resolutions. Once you have selected a resolution, click the OK button, and Windows 8.1 will shift to the new resolution.