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Make sure your external display is connected with correct cable and powered on
For connection cable, consult user manual for appropriate cable
Turn the laptop on
After the desktop loads press the Windows Logo Key + "P" then select one of the follow options
PC screen only - image will only appear on laptop and not on external display
Duplicate - same image will appear on laptop and external display
Extend - image will appear as an extension of your desktop
Second screen only - image will only appear on external display and not on laptop
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Connect laptop to external display using connection cable
Consult user manual for appropriate cable
Right-click any empty area of your desktop
Click Display Setting
Click on the Multiple displays drop-down list
Select one of the following:
Duplicate these displays - same image will appear on laptop and external display
Extend these displays - image will appear as an extension of your desktop
Mac
Make sure your external display is connected with the correct cable and powered on.
For connection cable, consult user manual for appropriate cable
From the Apple menu choose System Preferences
Open System Preferences. (System Settings on macOS releases 13 and later)
From the View menu, choose Displays
Click on the Arrangement tab
Mirror Display
Check
For macOS 11 and macOS 12:
Check the Mirror Displays checkbox if you would like to have the same image appear on laptop and external display.
Uncheck to have the image appear as an extension of your desktop
For macOS 13 and beyond
Hold down the option key and drag the displays on top of each other if you would like to have the same image appear on laptop and external display.To reverse this selection, simply hold down the option key and drag the displays apart.
