Its running Windows 7. It works normally whenever I am surfing the web or doing anything other than watching streaming videos. I can watch videos on youtube properly, but for some reason, the computer randomly shuts down when I try to watch something on hulu.com or even cnn.com. So it seems to happen only with streaming video. And I have no idea why, I thought it might be the graphics card overheating, but then I should have the shut down problem with youtube too.
So what could be the issue