Hi RayMcClellan
As you can see from my last reply I am satisfied there is no problem with Windows 8.1, to prove this I have fixed my shutdown and I know there are millions of other people who are running this software with this problem, hence it has to be your machine, i.e. Hardware and as I said above, it is normally the hard drive.
If you can not take out the drive and test it as I did, then you need to contact a PC Repair person to do this for you, he can then eliminate that item for you.
If it is not the drive then it can also be heat related with the CPU and/or Memory.
It is definitely not Microsoft's fault, as the Software is good, I spent two days talking to their engineers in America and they could not fix the problem, hence I looked at the hardware.
I am sure the problem you seem to be having is a hardware one, not the Operating System.
Regards.