In tip 2124 and link, I used a registry hack to prevent the last loggged on user name from being displayed when a user attempts to logon on.
To use Group Policy:
1. Use the Group Policy snap-in, local, for a standalone or workgroup computer, or the domain group policy for a domain member computer.
2. Navigate through Computer Configuration / Windows Settings / Security Settings / Local Policies / Security Options.
3. Double-click Do not display last user name in logon screen and press Enabled.
4. Press OK until you can exist the Group Policy console. If you used the local Group Policy, restart your computer.
NOTE: See tip 3819 » Gpresult freeware.