Pardon my pedantry, but technically Windows' equivalent of the root account is `NT AUTHORITY\SYSTEM`, although it's a little different in that it isn't an account one can use to Logon. You're right that `Administrator` is the highest privilege level interactive user account :) https://security.stackexchange.com/a/66747
This garbage and more is the reason I did my Framework 12's installation of Windows 11 (dual booting with FreeBSD 15) using this `unattend.xml` generator to disable internet requirement, disable mandatory Microsoft Account, disable intrusive spyware, disable disable disable: https://schneegans.de/windows/unattend-generator/
Sucks to have such an adversarial relationship with my own computer though. One shouldn't have to Know All The Tricks to avoid this shit.