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
Scroll down the Display window and locate the Multiple displays section
If the desired setup is to be separate monitors, select from the drop down Extend these displays
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.
Click Apply to save.