Trying to play this but unfortunately the game gets stretched horribly as I'm playing on a widescreen, and the graphics clearly aren't designed for that.

Is there any way to force the game to keep the proper aspect ratio? I'm using Windows 7.

UPDATE: I've got it working. In NVIDIA Control Panel, under "Adjust desktop size and correction", make sure "Perform scaling on" is set to GPU. Even though "Aspect ratio" is selected, this seems to have no effect if "Perform scaling on" is set to "Display."

Glad you got it sorted, but one thing I'd recommend is the HoMM3 HD mod. It allows you to play the game at almost any resolution, as well as providing a few tweaks, bug fixes, and convenient UI additions.

Second this. I had already fixed the aspect ratio like OP, but the interface controls added with the HD mod really did it for me.

Thank you! This should really be sticky post.