It sounds like your card may indeed be toast.
I suggest you have someone who is into PC hardware and can pay you a visit to do so and have her/him check up on it.
You could also take a look inside of your PC and just try to reseat the video card (if you know how to). Sometimes this fixes it.
All of this is beyond MegaGlest support, though. If you can't get help from a knowledgeable friend then your best bet is to check with a local PC repairs shop or maybe ask on some PC hardware forums.
The worst case is probably that you need to buy a replacement video card (>= USD 70,-)
Good luck!