I am upgrading several computers from 8.1 to 8.1 Pro.

All but 1 follow this procedure:
Run "Setup.exe" from ISO disk
files install and update, restarts twice
reboots to 8.1
click "Add features to Windows 8.1"
put in upgrade key
it runs for a couple of minutes then presents error "Something went wrong"
I reboot, at this time 8.1 begins upgrade process and ends up with 8.1 Pro.

On the one causing a problem:
run "setup.exe" from ISO
setup immediately asks for upgrade key, tries to update and gets something went wrong

If I try to "Add features" it asks for upgrade key, gets same error, but without loading files from setup, it won't upgrade windows.

Does anyone have a suggestion as to how to get this PC to upgrade? I have tried to refresh windows and have made a restore point, but I can't wipe the machine and start over. None of the others had to be refreshed.