Pcs are not supposed to shut down unless made to.
I need temps. Google for real temp and let me know the processor temps on idle first.
Google for orthos and run a blend test for 4-5 hours. Let me know if it shuts down or restarts. If it does, something is wrong. Also update the bios to a newer one. Google for hd tach and run error scan. If you see red square- there are bad sectors. I think asus has a software on their disk to check their rail voltage. Not sure the name but pretty sure its bundled with all newer (and some old) boards.