I used the DXWnd solution in a batch file as follows. Works like a charm.

---------
@echo off
start "" /MIN "D:\Games\DXWnd\dxwnd.exe"
"D:\Games\GOG\Robin Hood - The Legend of Sherwood\Game.exe"
taskkill /f /im dxwnd.exe
exit
--------

I configured DXWnd as in the previous posts.

I ran DXWnd as administrator the first time only, and after that I didn't need to run as admin again. I tried to run it the first time as non-admin and it crashed, but after running as admin once, all was OK.

ScottiePrimo's post worked!

Yet the game stutters with enemy line of sight. Any tips?

Yes indeed. Just read my previous post, where I mentioned a solution which seems likely to work for everyone.

Thanks NovHak, this worked for me like a charm. Can only recommend this solution if you have problems under windows 10.

For windows 10, you can go to moddb and type 'Robin hood the legend of sherwood' and click on the link which says 'Robin hood - Performance fix file'. After downloading the file and extracting it, copy Robin hood - performance fix file and paste it in the game folder then click on it and robin hood will start.
I have tried it and it works like a charm :)

This finally fixed it after looking for a working solution for over 4 years, thank you.

dgVoodoo actually works without problems.
This game is easy to fix. Desperados had (as you probably know by now, they fixed it 5th July) a more serious problem. mouse lagged and was blocked like it hit a wall. No DX wrapper I tried solved this entirely, some were better than other, but some had other problems as well.

I've tried dgVoodoo, the Aqrit Ddraw wrapper and DxWnd, but for some reason I could manage to get it working.
Tried a lot of different settings, but no succes.

Luckely I found this: Robin Hood - Performance Fix: gamepressure .com/download .asp?ID=59061 (without the spacebars, I cant post links for some reason)
Its a simple installer that you place in the Game-folder and run.
The installer wil install the correct versions of the Aqrit Ddraw Wrapper and DxWnd, with the right settings (for me atleast)

Simply use the exe to run the game from then on and your golden!
I hope this may help some of you, who are also not very versed in technical lingo!

So, this definitely fixed the performance issue. But when I selected German as a language (I want to feel the full nostalgia), it ran a bit slower again. Any idea on why this could happen?

I don’t know really, maybe the game is now launched with a working directory that’s different from the one where the dgVoodoo files are installed ? Or maybe for some reason, dgVoodoo’s configuration has been changed ?

So when people say it's running slow and it was "fixed," do they mean it went from 20ish FPS to 60? Or unplayable to 20ish? Because the difference between the game in the options menu and in-game is the problem I have. It's playable, but kind of annoying to execute orders with choppy mouse movement and lower frame rate. Can anyone confirm that they are getting 60fps or close to it and which method they used?

unplayable 21 fps so fix does not work

Did you manage to get 60FPS?