rawmilk905: According to a forum post a search returned, in the compatibility tab of an exe's properties "There is a special Resolution tab which will enable you to select the resolution in which the application has to be used." I see no such tab, only the option to force 640 x 480.
Yeah there is no such tab in windows. If anything you could force a program to 1280x1024 by using Nvidia control panel, but that wont help you here, because the game makes all of its rendering decisions based on its own configuration, so everything would still be 1024x768, just in the upper left (or it will at least be centered there, even if it draws some stuff on the rest of the screen). You have to get the game mod to work to play it properly at that resolution. I'll try again at some point, but ive already done a fresh install of GOG to 1.21 to 1.3 to my mod. Remember you absolutely must replace your game exe with the one I provide, as that is where the game controls its resolution. The mod vfs file just contains definitions for where to put the UI elements.
It's sounding like your exe isnt getting replaced for some reason.