From what I gathered from the Messenger discussions we've had, I'd say the problem is with your puter in general, and not with EHM. You said you have trouble keeping resolution to higher than 1024x768, although you have a pretty new display driver, and when you changed resolution, you had the taskbar jump to a completely different location. And now a game won't start at all.
I'd say, you either have hardware or software problem. And most commonly it's software than hardware in these cases. Looks to me like it's your Windows that's acting up and needs a spanking.
Try reinstalling Windows - that should fix any related problems. Especially if you've had a few months since your last install. Remember to make sure you have nothing too important at C: drive first, so you don't lose it in the process.
Anyways... that was my diagnosis.
