Windows 10 won't boot after freezing up and clean shutdown

1) What are the status of the files?
2) Were files backed up?
3) If not a backup image of the users folder may be able to be performed.

The operating system is corrupt (integrity violations)
The regback displayed 0 for the folders so this method was not able to repair the corruption.

4) See what happens with the hardware technique at this time.
a) Power on the computer and as soon as you see the Microsoft icon power off.
b) Power on a second time and as soon as you see the Microsoft icon power off.
c) Power on a third time and allow the computer to boot > what does it finally open to?
d) If the Windows advanced troubleshooting menu opens on the computer then attempt to open safe mode.
e) If opening safe mode fails then attempt reset save files.
f) If reset save files fails then boot to the windows 10 iso and run these commands:

See what happens if you uninstall that last Windows update:
a) Dism /Image:E:\ /Get-Packages
b) (Find the package(s) that were just installed by date. Run the following command on the last installed package:
example: dism.exe /image:E:\ /remove-package /packagename:Package_for_KB4014329~31bf3856ad364e35~amd64~~10.0.1.0
Reboot.

If removing the last windows update fails then the next step is to attempt a custom install with the Windows 10 iso.

First make sure that you have a Microsoft account.

Boot to the Windows 10 iso:
Instead of clicking in the left lower corner on repair your computer, click on install.
Do not delete any partitions as this is the method for clean install.
A custom install should be similar to reset save files.
Applications and drivers will need to be reinstalled.
See the txt and images in this link:
Custom Install Windows 10 | Windows 10 Tutorials

I've made backup of all the User directories.
I'll try these steps. With the last one what will happen to our WIn10 license that came with the upgrade from windows 8.1 to 10? Will we need to purchase another Win10 license? Thanks so much for all your help. I'll be back in touch soon.

If you upgraded from Windows 7 or 8 to Windows 10 then there is a digital license.
A disk drive should be able to be replaced without problems.
An operating system should be able to be clean installed.

Some have commented that having a Microsoft account adds to the protection.

This is a link to the Microsoft activation troubleshooter.
https://support.microsoft.com/en-us/...troubleshooter

The Microsoft server is linked to the Motherboard.
This is a link if there was a planned major hardware change (motherboard) and how to reactivate:
https://support.microsoft.com/en-us/...ardware-change

This is an additional link on the custom install method:
How to Perform a Custom Installation of Windows - Microsoft Community

Thanks!! The system is reinstalled (up and running) and has proven to me again that in the interest of expediency it sometimes better (and quicker) to just drop back and punt. I used to do this kind of stuff back in the Win95 - XP days, but as the company grew it just became easier to have images ready to re-image systems (Ghost), but that often obviscated the root cause to a problem. 3.5 hours to do the install as compared to 4-5 days trying to save the old install(???) I should have done a custom install from the start, but this situation was really infuriating. It seems that there was no HW error and the only event was a MS security upgrade the day this happened.
I wonder if this situation was due to the odd configuration of my mom's machine; I bought it used years ago for a really good price on eBay - it came with WIn7 Pro- that's why I got it. The Window key extraction tool on the Kyhi Boot rescue (by the way a fantastic tool) showed that the firmware was originally Windows Vista and then a retail version of Win7 was installed which I later upgraded through the Win 8 & 8.1 to 10. I never paid attention to the fact that although the architecture was x64 the Windows 7 pro was a 32bit OS and subsequently all the upgrades along the way were too. I wonder if the last MS update made a bad assumption because of the architecture to OS disparity and tried to stick x64 versions on top of the 32 Bit OS?

Well Thank you again for all the help. It was truly fun to do the down in the dirt nitty gritty again. Ha ha

That's great.
You are very welcome.
I'm glad to see it sorted.

Once you have the drivers, applications, and files to your satisfaction make a back up image using free software.
There are paid versions with more features.
(Acronis, Aoemi, EaseUS, Macrium, Paragon, etc.)
Macrium is widely used in Ten Forums.
Macrium Software | Your Image is Everything
Backup and Restore with Macrium Reflect | Windows 10 Tutorials