Thanks for the suggestions, I'll check out those links.

MeAndMyComputer said:
It makes me wonder if it would have been better to do the typical upgrade from your Windows 7 Home Premium to Windows 10 Home first as the configurations & Windows system files in which your Windows 7 Home Premium was operating would have carried over. ... Then do the clean install of Windows 10 Pro afterward.
Actually the original HDD with Windows 7 is unchanged. We just swapped it out with a blank SSD, then did a fresh install of Windows 10 Pro to the SSD. I can put the Windows 7 HDD back in and see how the memory looks now with the original dimms in their original locations. I'll have to wait until later, though -- someone else was using the system, and I'll have to wait until he's back so he can enter his Windows 7 password.

Eventually we'll want to end up with Windows 10 Pro running on the new SSD, not the original HDD.