¿Cómo puedo cambiar el nombre de mi usuario en el PC que me impone la cuenta de Microsoft?

Because this username is being referenced in a lot of places including registry, to maintain your user profile integrity, it is best that you create a new user instead, and then migrate your Microsoft account (if you have it linked) and data over.

Here are the steps:

1. Type netplwiz in the search on the taskbar and hit enter. When launched, click on "Add". On the next window, click on the bottom where it says to create an account without Microsoft email. This will allow you to define your own username. Make sure it doesn't contain space or special character. Set it up as a local user.
2. When the above user is created, back to the main netplwiz page, double click on this new user, go to the Group Membership tab, make it administrator. Save the change.
3. Go to Windows Settings > Accounts > Your Info. Click on "Sign in as a local user instead". Follow the steps to finish the rest. This will release the association of your Microsoft email to this Windows log in.
4. Restart the computer. Sign into the new user you created in Step 1.
5. Go to Windows Settings > Accounts > Your Info. Click on "Sign in with your Microsoft account". You can then use the same email address you released on Step 3. This will tie your Microsoft email address now to this new Windows log in.
6. If you have data at the old username folder, go to C:\users\old username folder, find them and copy them into C:\users\new username folder.
7. Type sysdm.cpl in the search on the taskbar and hit enter, go to Advanced tab, click on the "Settings" button at the User Profile section. Then delete the old user profile.
8. Launch netplwiz again, delete the old user from there.