When I start the exe (Win8.1) as administrator I get this error
"Der Prozedureinsprungspunkt "EnableNonClientDpiScaling" wurde in der DLL "C:\Program Files\Return ...Island.exe" nicht gefunden."

Can anybody tell what, what the problem is and how to solve it?

Thx!

Return to Monkey Island needs Windows 10 / 11 to run. It's a DirectX 12 only game.
Solution: Upgrade to Windows 10 or 11.

(btw, admin rights should never be necessary for modern games)

you can try VxKex , I haven't tried but apparently the game run fine with this software on win 8.1 and 7. (open source)
https://github.com/vxiiduu/VxKex/releases

Apparently it only works on Windows 7 so far. So if you are not on Windows 7 it doesn't work.

I missread the github description, at least he can have a try. Or could try the FAQ option to switch to vulkan render:

You first need to be able to see hidden files and folders:
'Open File Explorer from the taskbar. Select View > Options > Change folder and search options. Select the View tab in Advanced settings, select Show hidden files, folders, and drives and OK.'

Then locate the pref.json file.
The files are located in the following folder:

Windows: C:\users\yourusername\AppData\Roaming\Terrible Toybox\Return to Monkey Island
In Prefs.json add this line:

"renderer: "vulkan"" this is to force the use of Vulkan instead of direct x.

If you want to switch back to dx 12 replace this new line by: "renderer: "directx"" this force DirectX 12 (this is the default on Windows)."
Btw anyone knows how to delete a post on this forum?

Thanks all. Update to Win > 8.1 isn't an option.

So I installed it under Linux Mint 20.3 but unfortunaly I don't see anything. Can only hear the music.

MAybe the reason is this error
Xlib: extension "NV-GLX" missing on display ":0".
MESA-INTEL: warning: Haswell Vulkan support is incomplete

but I don't know how to solve it :(

Wish you all a merry christmas!

Does your laptop hardware meet the minimum requirements? Especially the one about the GPU.

Looks iike it does not.

Having to go to a forum to discover how to run a game in 2023 and then edit a CFG file with zero documentation certainly feels old-school right from the start.