PC is restarting itself, checked event viewer and it is coming up as a Kernel-Power ID 41. Help?

Recently bought and built a gaming PC. Last few weeks it has been randomly rebooting with no warning. The system will restart then come up with the black asus motherboard screen (not a blue screen). So I checked the event viewer and it has said it is a critical error called Kernel-Power. I have looked online on how to stop this and can't seem to fix it. Does anyone know what the problem might be... could I have a faulty power supply? PC is less than a month old. Can post specs if needed... Thanks.