However, showing and displaying of user accounts on the Welcome Screen is probably a weakness in the security point of view, more so if the user account is intended to be a hidden or backup user account. In fact, there is trick to make user account or administrator account that normally been listed on the Welcome Screen to be hidden from view.
In order to hide a user account (which also means create a hidden user account) in Windows XP, Vista, or Windows 7, just go to Control Panel User module and create an additional user as usually do (Control Panel -> User Accounts and Family Safety -> User Accounts in Windows 7 and Windows Vista). If you already have an existing user that wants to be made hidden, invisible or disappeared from Welcome Screen, then go straight to guide below.
1. Run Registry Editor (RegEdit.exe).
2. Navigate to the following registry key:
Note: If SpecialAccounts and UserList is not found, create new sub-key and name them accordingly.
3. Select UserList, and in the right pane, right click on any blank space, and point to New -> DWORD (32-bit) Value.
4. Name the new DWORD registry value name as the exact same name that match the name of the user account to be hidden.
For example, if the user ID of the user account is John, the name the registry value as John.
5. Double click on DWORD registry value, and set the value data to 0 in oder to hide the account from Welcome Screen.
Tip: To display the user account on Welcome Screen again so that it’s visible again, delete the registry entry, or set the value data to 1.
6. Exit Registry Editor.
7. Log off or restart computer to make the change effective.
Tip: In order to login into Windows using an user account that has made hidden and invisible, just press Ctrl+Alt+Del to bring up Windows Logon dialog, and then type in the user name and password manually.