Computer peripherals turn off but not computer itself?

[Liquid]

Hello there, recently, I've been having an issue with my PC. Randomly, all peripherals (Monitor, Keyboard, Mouse, Speakers, etc.) turn off, but the computer stays on, and I need to turn it off by flipping the power off, and once I turn it back on, it boots normally and such. Like I said, the times this happens seem to be completely random, though I believe it has only happened at night, but that may be just coincidence. I have used virus scans, and nothing has come up, so I don't believe that's the issue. I haven't made any significant hardware changes recently either. Does anyone have an idea of what could be happening?

Thanks in advance

 

[Tmagic650]

Get into the motherboards bios by pressing a key noted when you first power up the computer. Look for "hit F? for setup" or something like that. Reset the bios to defaults