Luckily, it's pretty easy, and there are several ways to change the administrator name in Windows 11. As long as you already have access to the administrator account, you can change the name to ...

If you are unable to change the domain name in Windows 11/10/Server, fix the Name resolution (DNS) issues and update the Group Policy settings.

Windows 11: How to set up a local network If you use more than one computer in your private or business environment, you will benefit from a local Windows 11 network.