I have never experienced this problem but I would suggest you to try booting up some Live DVD Linux distribution like Ubuntu. If you card is working properly there than it will most likely be software problem which you could somehow debug and resolve. If you experience the same problem under this environment than the card is most likely damaged and you should contact your vendor. I wish I could give you better advice but I just don't have required computer hardware skills.
I guess I'm a little confused, how are you able to see WIndows to install the drivers if you have "No Video"?
Can you see the BIOS on bootup? If you can, check the BIOS and make sure that graphics are set to the card and not the on-board graphics. Then when you run Windows Update, check the "Optional" tab and look for the update there.
Try delete your all of driver folders with Display Driver Uninstaller follow the instructions delete with this program and install the appropiate driver. Your issue will be solved with this.