Why wont the resolution change

Myki

When I first started Crossfire, the resolution would not fit onto my screen. I could only see the top left portion of the game and the rest was cut off. I was only able to reach the options to change the resolution by changing my desktop resolution 2048x1152 (not the in game resolution). Of course, by doing so, a portion of my desktop background peeks out on the sides and bottom of the game, and when i try to change the in game resolution, the game says that the setting have been saved, but nothing happens, whether its 800x600 or 3840x2160, the game runs at the exact same size, even in windowed mode.

Can someone help?