Hi @DamDam,
Can you further elaborate on your issue regarding duplicating/projecting Display?
1. Is there no option for ‚duplicate‘ in your PC settings at all? or…
2. do you want to just project your secondary machine to multiple screens?
If #1 is the case, can you please check if your primary graphics adapter is updated and has WDDM version 2.0-above?
You can check the WDDM version by opening dxdiag.exe.
-Search „dxdiag“ on the search menu, or simply do Windows key + R, then type „dxdiag.“
-Then click the Display tab.
Check the „Driver Model“ box underneath the „Drivers“ box.
You can also refer to the chapter „Windows 11/10 Desktop Duplication (mirror) option not available“ in the user manual https://forum.spacedesk.netuser-manual/#item_482
If #2, please refer to this topic, which covers duplication across multiple screens.
Link: https://forum.spacedesk.netforums/topic/duplicate-to-two-other-displays-on-windows-10/