Well, this was done on purpose since Vista. Vista and 7 follow EDID
no matter what. However, some hardware hacks are avialable for CRT (old tube) monitors.
But nowadays with LCD monitors the story is different, because they use fixed number of pixels (yes, lower resolutions are interpolated). Thus, forcing LCD monitors in higher resolution (higher than intended by manufacturer) may cause huge problems with quality of image.
At the same time looks like some Nvidia cards allow custom resolution
(with Nvidia drivers, not generic).
But I have not tried that myself, so can not comment on that.