I think that from what I see, he will have one small partition for w10 backup. The rest is open partition for everything else. That's all that should show up. If they changed that, it is news to me. Could ms have a bug in there system? Sounds like it! ISP's should always do the two partition. I would contact ms and see if they would help with install. I called them when my passkey wouldn't take and they fixed it right on the phone for me. Give them a try.