Display Settings for Multiple Monitors - Windows
To change the Display Settings for a Multi-Monitor setup in Windows do the following:
Right Click on an empty section on the desktop>Select Display settings
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Scroll down the Display window and locate the Multiple displays section
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If the desired setup is to be separate monitors, select from the drop down Extend these displays
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Put a check in the box for Make this my main display if the selected display will be the main monitor.
(In this example Screen 1 is selected and highlighted in blue)
Drag the monitor to the desired location matching the setup.
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Click Apply to save.