Computer restarts when streaming video online

Hi,

My home built PC reboots when I watch streaming video online. I use Chrome but I've tried IE and it happened with that too.

I don't get a BSOD, it just reboots out of the blue. There're no errors listed in the Event log apart for one where the computer is complaining that it just restarted without warning.

I'm running Windows 7 64bit. I've checked my BIOS and it's the latest version, I have the latest graphics card drivers. I've used Speedfan and the cpu temp is 45-50C. I can play games fine without it rebooting.

One of the first things I installed was Windows Security Essentials, so I should have been warned if a virus had snuck in.

Any ideas what might be causing this/steps on troubleshooting this issue?

 

Usually, it's the inability of Windows to reset the driver, or an instability in the GPU/Video Card or even the CPU. I stress USUALLY.

Are you overclocking your GPU, or CPU?