Pc crashes when playing video on Steam and Hulu

So I am hoping I am just over looking something simple but my pc runs fine otherwise. It plays any game flawlessly, does fine on memtest86, Prime95, Uningine Valley. But tonight I was browsing through Steam and clicked to watch a game trailer and the computer froze completely and I had to hard reboot.....Strange but ok so I tried again and same damn thing. Went to YouTube and no problem so I went over to Hulu and bam the computer froze again so another hard reboot and went back to Hulu and just like the first time it froze up solid. I am at a loss here as it seems very strange to only be affected by playing a video and I am trying to figure out where to start diagnosing this. I am trying to work all the bugs out before I start oc and was under the impression I was pretty much done until this tonight. Just trying to get my build wrapped up so thanks in advance guys. 

My Specs:

Win 8

Fx8350 no oc

Asus sabertooth r2

G skill Ripjaws 1600 32gb

HIS Reference R9 290 no oc 

Coolermaster V1000

The OS lives on 2 Corsair Force Series GT 90gb ssd's in raid0 


ok, so the first thing is your PSU. you didn't seem to mention it in your spec list, its possible that when you play a game, when your cpu and gpu are asking for more power your psu can't handle it. this can also be an OS issue, if you have a spare usb put ubuntu on it and make sure it has persistence (google how to as it sounds complicated) once you have done that try and run some games off there (if you have any linux compatible games) if it does it again then its a hardware fault and id advise looking at your psu first.