The server's actual display settings cannot be edited since the display in RDP (Remote Desktop) is redirected from your local machine's settings. However, you can adjust these settings within your .RDP file by following these steps:
1. Right-click the .RDP file and choose Edit
2. Display tab (here you can edit the display settings)
3. Check the "Use all my monitors for the remote session" box
4. General Tab / click "Save"