My computer glitches when i play a game or video

[bentrimbey]

System Setup:
MB: ECS A885GM-A2 (V1.1) AM3 AMD 880G SATA 6Gb/s ATX AMD Motherboard
CPU: AMD Phenom II x4 955 BE
Ram: 16gb G. Skills Ripjaws series
Video: Asus EAH6850
HD: WD Caviar black 1tb
PSU: Rocketfish 500w
Windows 7 64 bit

my problem is that when i play games or watch videos my screen goes black and i have to reset my computer and when i do it says windows had an error and it is really annoying. So do i need a better power supply or what? Also I have tries this on 2 different models of moniters

 

[amuffin]

rocketfish power supply LOL that is most likely your problem.

 

[bentrimbey]

rocketfish power supply LOL that is most likely your problem.

Ya, but it did the same thing with my corsair VX550.

 

[amuffin]

Are all drivers up to date?

 

[truegenius]

bios update or a new power supply or graphics card driver update (may be with a fresh install of window)