Computer just restarts

[Mikeepower]

After leaving my PC on overnight and during school, it randomly just restarts. Has happened twice overnight, and twice during the day. No reason given, just load up my monitor and computer has closed everything and loaded all my startup programs. I would like if someone could tell me why this is happening and how I can fix it. This never happens when I'm using my computer, no matter how long I've been using it for. I have the event viewer logs from 2 of them and screenshots have been attached (both general and details tabs).
First Time:


Second Time:


Specs:
i5 4690k
GTX 960
8GB RAM
1TB HDD
480GB SSD

Thanks

 

[DelJo63]

Error 41 is a POWER issue -- see this.