Trevor, thank you very much for your quick and helpful email. I did what you suggested, and still could not do the upgrade. After nearly 2 hours of trial and error, I found the solution.
From the Photoshop "Help" menu, I found a way to update my account preferences - oddly enough, Photoshop was set to NOT show me updates. Nowhere else did any source or account management say anything about checkbox preferences to show or not show updates.
Once I clicked Photoshop on, I was invited to upgrade.
Thanks again for your help. You got me started to resolve this issue.
Jonathan williams