Primary Display Went All Grey with lines through it after being idle?

I have two monitors in my build, my PC was in lock mode (Windows 8.1) and I left it with the monitors turned off like I usually do. When I turned them on the first one was normal, but my primary display was like this:

63252d1435496585t-intermittent-stripey-screen-crash-amd-r7-265-a-stripey-screen-1.jpg


I forced a restart and it booted fine, It said "Video Hardware Error" and that was it. I have the new Crimson Drivers if that's the issue.

What could the problem be?

UPDATE:

I noticed that the PC "Shut Down Unexpectedly" before I forced restarted, so that means something cause the PC to crash, and then boot with these grey lines... PSU issue? :/

- Sam
 


Thanks. I've only had my PSU for 10 months so I don't think it's that, plus the PC was idle and the power supply handles games like fallout 4 for hours on end fine. I checked that the GPU was seated fine, and it was. All connected too. When I restarted the PC, it was fine and I haven't seen the issue again. I did reinstall windows after this, so I hope it will be fine now. Do you think this was to do with the AMD Crimson Drivers?

- Sam