I'm not sure what else to suggest not mentioned in the forum topics you've already found (like Game Loads for ever)...

I don't know if this will make a difference if Lockstep mode didn't, but try starting the game, then start the Task Manager (Ctrl-Shift-Esc or right click an open area of the Task Bar), switch to the Processes tab, right click on Divinity2.exe and select 'Set Affinity...'. After that, try unselecting all but one of the cores, apply and test the game.


You could try playing the game in a virtual machine; performance may not be as good, if it works (the overhead probably wouldn't be noticeable, though, given the game requirements), but a couple people did that with D:OS EE to confirm issues were system related, before resorting to reinstalling Windows.

https://www.howtogeek.com/196060/beginner-geek-how-to-create-and-use-virtual-machines

https://www.extremetech.com/computing/198427-how-to-install-windows-10-in-a-virtual-machine

Not long ago I tried the game in XP Mode in Win 7, to see if that would work, but I don't think XP Mode was designed for games (I had set it up to use an old scanner, when the software and drivers had issues in Win 7), though I didn't check the video configuration other than confirming DirectX 9c support, or do much in the way of troubleshooting.