The Windows welcome screen displays all of the local users on the system, except the built-in administrator account that was created during setup. If you want to hide the Administrator account or a specific user from the list, you need to create a special value under this registry key.
If you are not familiar with Windows Registry Key Names, do not to worry as you only needs to know how to launch the Registry Editor then navigate to the UserList to fix the settings.
Under this key you simply create a new DWORD value – the name matches the users name exactly, and the value is one of the following (Decimal format)
0 – Hides the user just from the welcome screen
1 – Shows the user on the welcome screen
This is should be useful in getting any Administrator account of the Welcome screen in a public setting such as a library or classroom so that it will not be brute-forced. Be mindful that in these settings, the computers are often protected by SmartShield by Centurion Technologies so it has to be disable to make the changes.