@Carolv(op) Perhaps try this.
Go to Microsoft.com on your browser. Sign in with your user name and password. When you are signed in click on you name (top right of page) and then click on "View Account". You should then be able to edit your user name and password.
I hope this helps you. If not let us know.
It looks like they "simplified" the design. You used to be able to rename accounts in previous versions of Windows but ... I cant find a way to do that at the moment. maybe there's something buried somewhere.
I suppose you could create a new local account make it an admin, then logon with it and delete the original account, then associate the new account with the MS account... maybe.This is what I was finding also. No way to change user name. Just talked to Tech support and I guess the way to do it is when you first set up the computer, to use a local account with my name. Then after set up, change over to a MS account with my email address.
Don't know why MS has decided to use the first 5 of your email address instead of the actual name you type in.
Anyway. This SP4 is going back also. Have a dead pixel and other issues. Seems to be loosing battery fast, looses battery percent even when shut down, sometimes won't turn on, sometimes won't recognize the keyboard, clicking the pen doesn't always work. It's a shame the first one had a defective display cause I didn't notice any other problems with it. But the screen would bleed through the desktop making it unusable. I would get 2 transparent screens on top of each other.
Hopefully 3's the charm.
You should have the option to log in with a different account. Try it.
I suppose you could create a new local account make it an admin, then logon with it and delete the original account, then associate the new account with the MS account... maybe.