I had the same problem with my Toshiba laptop. One month after the warranty ran out the screen went black and would not come on anymore.
Before this happened, I had been getting messages from action centre that the video graphics display adapter had a problem and it would shut down for a second or two and go back on. This happened for months before it shutdown permently. Did you get these messages for a while before it shut down totally on you?
If your laptop is under warranty still, I would get it in pronto and bring your warranty with you.
If you are not using a laptop, but are using a desktop, you can probably just exchange the old video card for a new one. It is as easy as adding more ram. With the laptops, I think the graphic cards are all welded into the motherboard. I hope I am wrong about this, though, because I am having the same problem all over again but with a new laptop, not Toshiba, but Mac Pro.
I hope you are able to get your problem solved with a new graphics card if you use a desktop computer, or that your laptop is still under warrantly.