Plugged it in, downloaded all Windows updates, latest drivers, Steam and so on. I run Napoleon Total War to see how it runs... and it crashes immediately, just when tweaking the graphic settings.

Are you getting The GPU failed to perform image processing error with Error Code 999, 1, 40, 702, 700, 38, 5, 77, 59, etc. in DaVinci Resolve? DaVinci Resolve is ...