Why is laptop shutting down?

[learninmypc]

No screen saver is activated, power options show never when using ac power yet when I did a defrag last night, it shut down. When I started it back up, the defrag continued. It has been on ac power all this time . Its this laptop

 

[DelJo63]

With AC Power, the reasonable guess is simple over heating - - needs to be opened and cleaned IMO.

 

[learninmypc]

I will tell the owner about that, thank you.