Why does my computer white screen on Youtube?

[laungst]

So far, its happened 3 times, only while I was watching Youtube. My computer just goes this dark white color and a loud buzzing noise comes out of the speakers. I have to hold in the power button to get it to turn off. It seems like it happened while I was hovering my mouse over the ads below the video (or that could be just coincidence). I have Norton Antivirus, and I ran all the scans. Can anyone help me fix this or at least tell me what the problem is?

[Meng]

You do realize that Norton screws up a lot of websites. I tried Norton.... messed up facebook and youtube lol. I would recommend you use Avast! free anti-virus because its the most effective free anti-virus that doesn't effect web sites and does not slow down your computer. Hoped this work