Not to sound patronising, but have you tried the in game settings? I've never played the game myself, but most these days have an option in the menu. And the .ini file could just be a bit dodgy. Really, having never played the game for all I know they could have last minute disabled full-screen.
You are about to answer a thread that has been inactive for more than 6 months. If you still wish to proceed, please ensure that your posting is original and does not duplicate or overlap any prior responses to this thread.