Upgrade from Windows 7 Home to Windows 10 Pro

https://superuser.com/questions/1151555/upgrade-from-windows-7-home-to-windows-10-pro

You can acomplish this by doing the following. You will need to upgrade your installation to Windows 10 Home. You then upgrade Windows 10 Home to Windows 10 Professional, using the generic license key, VK7JG-NPHTM-C97JM-9MPGT-3V66T. Once you are upgrade to Windows 10 Professional, navigate to Settings > Update & security > Activation > Change the product key and enter your Windows 8.1 Professional license key.