I had the same problem on my two asus all i had to do was disable the fast start up in the power section, i thought the same cpu cmos had a problem originally but this action fixed it

noticed other windows 10 problems at startup rebooting loop which they had to turn off the fast boot option, worked for for my shut down at start up as well

I have two asus m4a78lt m le pc , after installing windows 10 they both will shut down just when the windows 10 window shows, If i press the restart power button again straight away they will start...