If you are having problems with low FPS and audio sync despite trying out different settings, try renaming the executable file in the game folder from x64 to x32. Use the x32 exe file to launch the game instead of going through GoG Galaxy. You won't get achievements but at least you can enjoy the game.

These "fixes" are related to driver profiles.

I haven't played it on PC in a while, but TNO had a completely screwed up Nvidia profile from after the "Game Ready driver" to every driver released for like a year and a half or something. It was crazy.

The actual "renaming" fix doesn't do anything other than make it so the game doesn't use the driver profiles. The same effect can be gotten by using a tool to delete the graphics driver profile for these specific games.