My PC just powered itself off completely. It’s the first time it has ever done that! I’ve just hit the power button and it has powered-up and everything seems to be back to normal. Where should I start to troubleshoot if this happens again?
Check the Event Log (Start->Settings->Control Panel->Admin Tools->Event Log) and watch your CPU temps.
Also, make sure that the Automatically Reboot option is unchecked under (Right-Click My Computer->Properties->Advanced->Settings under ‘Startup and Recovery’).