This policy setting forces the user to log on to the computer using the classic logon screen. By default, a workgroup is set to use the simple logon screen. This setting only works when the computer is not on a domain.
If you enable this policy setting, the classic log on screen is presented to the user at logon, rather than the simple logon screen.
If you disable or do not configure this policy setting, computers in a workgroup will present the simple logon screen to the user at logon.