Wolfie - I am using my Microsoft account. One question: will changing to a local account affect access to all the computers on our home network? I'm having big issues with that too and don't want to add another variable to the mix.
Trouble - Thanks for this. If Wolfie's suggestion to move to a Local account isn't an option due to network issues, this solution makes sense to try. My concern is that I'm working with Windows10 Pro. The author says there are 6 ways to do this in Pro, which is why he focuses on Home. However, I've tried every way I can find to do the rename, and nothing has worked. Going to the built-in administrator is the only remaining option, as far as I can tell. Do you have any idea if this process can also apply to Pro?