PS: Just to confirm what I'm seeing:
PC came bundle with Windows 10 Home
Clean installed Windows 8.1 Pro and activated (wiping existing partitions)
Use MCT to upgrade to Windows 10
MCT wizard moaned that I can't keep settings and apps because I'm going to a different edition of Windows 10
The last page of the MCT wizard, before starting install says, "To confirm, you're going to: Install Windows 10 Home"
So it's clearly preferring the embedded key to the version that's currently installed. I expect that after following Charles' advice after the upgrade to get to Pro, then doing a clean install will force
Home Edition.
I'm actually an IT Pro and I'm thinking of the implications this has for corporate deployment. We have a Microsoft Site Agreement and I'm thinking that if we buy PCs with Pro on (that have an embedded
key), but deploy Enterprise as part of our agreement, will it force Pro, with us having to visit each machine after deployment to activate Enterprise!