I built a Windows PC that has started failing every hour or two while I'm playing games. Both monitors lose their signal first, followed a few seconds later by the keyboard, mouse, and other peripherals. The computer itself appears to remain powered on, but it becomes completely unresponsive and won't shut down normally, so I have to hold the power button. What could be causing this, and how can I troubleshoot it?
2 Answers
When the displays go black, try pressing Windows + Ctrl + Shift + B. That shortcut resets the graphics driver and can restore the video signal if the driver has crashed. If it works, the GPU or its driver is a strong suspect. If the keyboard loses power too, though, the issue may be more serious than just the display driver—possibly GPU power, overheating, the power supply, or a motherboard freeze.
Check Windows’ Reliability Monitor by searching for “View reliability history.” Look at the entries around the time of the crash. If it only reports that Windows wasn’t shut down properly, that may just be because you had to force the power off. A lost display signal during gaming can point to a graphics card or graphics-driver problem, so updating or clean-installing the driver—and testing the GPU if possible—would be worthwhile.
I checked it, and the only event shown is that Windows wasn’t shut down properly.

I’ll try that next time, although I think the keyboard loses power a few seconds after the monitors do.