Blue screen of death!! Help!

I installed my new 7850 last week or so on my fairly new computer which is 8 months old with A8-3870k cpu with integrated graphics, kingston 8GB hyperx ram, and asus motherboard with this psu http://www.newegg.com/Product/Product.aspx?Item=N82E168... and it worked perfectly. A week or two later I got a blue screen of death. My pc restarted and it worked fine. The next day(today) I got a blue screen of death again 2 times in a row before the pc worked again. I'm a little worried, I don't want my pc to crash and have to restart windows deleting all my files. What's the cause of this? I already did a full system scan with nortons finding no viruses and used ccleaner to clean the registry.