Connecting Computer to an External Display
Windows
Windows Method 1
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 following 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
Windows Method 2
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
Open System Settings
From the View menu, choose Displays
Click the Arrange… button
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.