Simple. Just as you would tweak the game compatibility mode. Find the GTA executable. It's called gta-vc.exe. Right click, properties. In this dialog window, check the box that reads Disable visual themes. And that's all you need to do. Launch the game, your mouse will now work properly and you can go about Miami pimping the scene like a champ.
So I downloaded GTA Vice city from steam on my computer, its Windows 10 and the mouse isn’t working at first I thought it’s locked and will be…
And the only fix is frequently opening the steam overlay. Odd. Might just be a windows 8.1 thing. Going in and out of the pause menu causes mouse to become non-functional until overlay is opened and closed again. No idea why this is a thing. It has a workaround for now though. Kind of inconvenient, but hey at least it's not totally broken
After playing you can use task manager again to run explorer.exe to bring the desktop back. Going to properties and in compatability tab clicking ''disable visual themes'' worked for me for both VC and SA. Once you set it you don't have to change it again every time you enter game. You can try turn standart settings.