If you have already installed and registered Windows 10 with the motherboard, then a clean install is the way to go. You will not need the reg "Key" again, just leave the request blank and move on (next)
One thought, is it supposedly easier to just upgrade as your programs are already installed rather than having to manually install them & baring any problems you can just keep on moving. I did install Win10 from disc (clean Install) before I went back to Win7, that is what I like to do but since I just put in Win7 I thought I might escape with an upgrade.
If I understand this correctly since I did install Win10 prior to going back to Win7 I wont be able to use the upgrade route? I did put in my Serial # when asked during the Win10 installation so that y would force you to a clean install, Since I did go to 10 & then back to 7 I would like to do this quickly but if that wont work I will just have to do a clean install. The reason for the move back to 7 was my intense dislike of Edge & being held prisoner to it but I have now found out how to disable it so I wont have to fight with it. Prior posts on that.
I do have the Win10 disc I downloaded and burnt to a DVD Disc.
Thanks to both of you for the input.