I have had success! I created the ISO using the media creation tool on my SSD. I then proceeded mount & launch the installation off the ISO. I got the following message after a failed attempt: 0xC1900101 - 0x20004.
This led me to the following link:
https://support.microsoft.com/en-au/help/10587/windows-10-get-help-with-upgrade-installation-errors From there I did a clean restart into Windows. (There was link that explained how to perform a clean boot in Windows.)
I tried to upgrade again from the ISO. Failed again. I continued to remove hardware from the PC (first my sound card, then my DVD drives). But the PC continued to hang at about the same point. All I could do after each failure was hard reboot the PC & it would restore back to previous version (1607).
I finally removed my network (Ethernet) connection. Then everything worked.
Thanks for your help. I don't know how many days over the past 6 months I have spent trying to get this upgrade to work.