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I just installed the game and it's working flawlessly on windows 10, except that the top bar persists as it can see on the image: any idea how to remove it?
I have the same issue, made GOG Support notification. Attached screenshot.
I've recently completed Desperados in its entirety and found no way to disable the title bar whatsoever. All the possible Dxwnd hacks failed.
After several missions I learned not to care at all.