On your screen/monitor look for an option to stretch it horizontally. Try that maybe?

does your video card setting/option got this kind of selection with a tick box (overide the scalingmode set by games and programs)?

if it got one try ticking it and play the game,

and try to look around here in tech support cause you can have answers cause of same issue like yours

If I remember correctly, NF isn't natively made for widescreen monitors. (On my friends' 16:9 monitors, the text looks stretched out, but on my OLD 5:4 (1280x1024) monitor, they look nice).

Your graphics card/controller should have an option to stretch images to fit screen.

make sure you have NF opening in max window, that will solve your issue mate

If your playing on widescreen laptop then not much you can do.

My laptop does the same, only way around it its to use a a normal computer monitor with your laptop.

Download the latest Nvidia drivers, then right click your desktop and go click "Nvidia control Panel". Under Display, click "Adjust desktop size and position", and change the scaling options to Full Screen and the resolution you want to use.

I'd recommend playing with the black bars. Stretched screen made judging AA angles that much more difficult.
So I did the opposite of what you did but in my case, I did the actual adjustment to my monitor which was
doing the stretching. If these suggestion don't help, try tinkering with the options on the monitor itself.

Thank you all for the support! I went to the control panel, and as I was about to start messing with it, I just decided, I could live with it. Then when I alt tabbed back in, oh look, its fit to screen... nfty.

check for graphic properties. scaling mode should be full screen.