[deanhills]

You have upgraded from Windows 7 home to Windows 7 Pro. So the Home Edition gone. Windows 10 will pick the current edition and it's key. Whatever the one Properties in My Computer shows you. I don't think Mother board has any connection to that. Key is part of the OS it's not on Hardware. But before you upgrade make sure to write down the serial and key if you don't have the original cover anymore. You will  need it if you are going to do a fresh upgrade not on the previous one. If not then it shouldn't be a problem. Installer should pick the one already in there.

Hmm second thoughts if you are doing to do a fresh installation. There are conflicting info about it. Also I found this which you might want to read,

https://answers.microsoft.com/en-us/wind...e32e85e645
https://www.bleepingcomputer.com/forums/...oduct-key/

Thx @xdude.  When I click on Windows System in the Control Panel, it does show Windows 7 Professional and that it is activated.  Also, when I use a tool to check the Windows Key it comes up with the product key that was used for Windows 7 Professional.  What is interesting when I paid closer attention to the last Product Key was that the key was for a 32-bit installation.  So I have a Product Key for 32-bit, however that activated a Windows 7 Professional 64-bit OS. When I did research, looks like Microsoft doesn't mind, however on a one-off basis.  You only get one chance to decide 32-bit or 64-bit and can't change back to the other one after that.

I've got a slight worry, that the Windows 10 Professional upgrade went so well with my ThinkPad Laptop because there was so little on the laptop.  Even the Windows 7 Professional on it was almost unused as far as updates were concerned - almost pristine copy.  Maybe the less one has on a computer for Windows 10 to analyze or worry about, the better.  Wonder whether it may be a good idea for a reformat of the hard drive of my desktop computer before I start the Windows upgrade followed by a clean install.  Hopefully the License for Windows 7 Professional will still be good for the upgrade.