Remove 'Administrator' account Windows 10

I have trouble removing the administrator account from my notebook. It was created when I wanted to access some read-only files and I wrote "net user administrator active" in cmd. (didnt work out tho) I tried removing it but there is not an option to do so. The delete account button is not available in user settings and I can not remove it from the settings menu. It seems that its not a real account but when I turn the notebook on I have the option to sign into that account.
Any ideas?
thx