My screen just freezes but does not restart.
Have you tried cleaning the inside of the computer especially the fans and heatsink make sure there is no fluff on the Fins of the heatsink.
Not got a clue why mine does it beginning to think maybe my PSU but will wait till things deteriorate further.
Are you using W10 home in all my Googling it seems that most of those with this sort of problem are using it. Probably just a coincidence maybe that is the most popular version.