The more info you post, i don't know if you can get from where you are to where you want to be
Here are some quotes from your posts, and my response.
If there is a way to upgrade the Win 7 and give Win 10 an 8.1 key at the time; simplification would result.
I can't answer your question.
Someone at sister site Ten Forums might be able to give better help.
Windows 10 Forums
I am in my second full day of updating 7 to 8
Are you trying to update from 7 to 8 on the old motherboard or the new motherboard ?
Did you find a Win 8 media to install from, or do you mean 8.1 ?
I looked into the existing Win 7 and found what appears to be an OEM key.
To be sure what type of license you have run MGADIAG.exe:
Windows Genuine and Activation Issue Posting Instructions - Windows 7 Help Forums
If you have an OEM license,
I've read sometimes MS will issue a new key for transferring to a new MB because of hardware (MB) failure.
You would have to get the right support person on a phone call and explain the situation.
You can search for info about that possibility.
From your input, it should work (I.e., move settings and apps) if I just moved the Win 7 image to the new MB using Reflect's (backup system) function that does that.
I don't know if Macrium backup can reliably move an OS to a new PC (motherboard).
Here is a tutorial for transferring an OS to a new PC:
Windows 7 Installation - Transfer to a New Computer - Windows 7 Help Forums
Yes I need an upgrade. There are applications that cannot be reinstalled. They also may not work after upgrade; but I won't know until I try.
If you have applications that you need to keep and cannot be reinstalled you might want to look for an exact replacement motherboard and keep using Win 7.
You have to decide if those applications are critical, or could be replaced with newer programs, etc.
Win 7 can not be upgraded to any other version but Win 8 if all settings and installed programs are to be moved intact.
I think you're right about that, see screen print from Shawn's tutorial:
http://www.eightforums.com/tutorials/2234-upgrade-install-windows-8-windows-8-1-a.html