Apologies if this has been answered already, I've been pulling my hair out trying to find how to fix it. Everytime I load NWN Diamond (the free one) it's like the resolution is jacked up? The game appears to be trying to load 800x600, but is being stretched to my desktop resolution. I've tried with overrides on and off from the graphics options.

I'm currently running Windows 10 on a Macbook Pro 2015 13" (8gb ram, Intel Iris 6100).

IIRC the game defaults to 800x600.

You need to change in game resolution to what you want by following menu sequence here:
https://www.gog.com/forum/neverwinter_nights_series/game_in_1920x1080_fullscreen_doesnt_scale_up/post9

You might want to check what Windows is running your resolution as, and what is available. I am not sure what you get on a retina Macbook under Windows.

Im having resolution issues as well. As soon as I changed the in game resolution to 3840x2160 for my uhd tv my mouses left clicker stops working and the game window is super small. Cant do nothing with it except cntrl/alt/dlt. Restarted and still the same. Ive resorted to reinstalling the game already.

Running Windows 10, Z170 chipset.

<EDIT> Not sure if left clicker not working has anything to do with changing the resolution. After reinstall its happened again while in the setting menues. This time I was staying far away from the resolution options. Ill just leave it at 800x600 which doest look bad and it fills the whole screen at least unlike the uhd options.

<EDIT2> Left mouse button was still freezing up in start menus so I changed compatibility mode to Windows XP service pack 2 and so far so good except when I mess with the resolution.