Where could a Windows 8.1 user have disappeared from the welcome screen?

Question

System administration

Good day to all.
Today, when I turned on the computer, only one user was displayed on the welcome screen. He is an administrator.
Until today there were 2 users: admin and regular user.
The second user account exists and is displayed in the control panel.
The files are there too.
Please help with advice or an answer to a question.

Answer 1

The problem was solved radically: a rollback to the factory settings.

Answer 2

In the registry, in the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\UserList branch, we are looking for a parameter with the user name with a DWORD type and a value of 0 and delete it. The user will appear in the greeting.
It is necessary to hide - go to this branch and create a DWORD parameter with the user name, and the value 0

Answer 3

...The second one is hidden...