You can do this by clicking the button in the lower-left corner of your screen shaped like the Windows logo.
Once you restart, you will see your new username on the sign-in screen. Here’s how to change an administrator name on Windows 10: Make sure to restart your device after you’re done.
This will take you to Microsoft’s website, where you can edit your profile. If the administrator account you want to change is linked to a Microsoft account, you can change an admin’s name by going to settings > Accounts > Your Info, and then clicking on the Manage my Microsoft Account option.
