1. Right-click on a blank spot on your desktop and select "Display Settings"

2. Under the "Select and rearrange displays" section, drag and drop each display to rearrange them according to their physical layout on your desktop.

Quick tip: If you're not sure which monitor you're selecting, click the Identify button to figure out. If one of the monitors isn't showing up, make sure it's receiving power and connected correctly, and click the Detect button.