Removing the Domain Drop-Down List from the Windows Logon Dialog Box

Q: How can I remove the domain drop-down list from the Windows logon dialog box (i.e., the dialog box that opens when you press Ctrl+Alt+Del)? I want to make it impossible for users to select the wrong domain when they log on to Windows.

A: To remove the domain drop-down list from the logon screen, you must make the following registry change on all your Windows client machines: In the HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsNTCurrentVersion registry container, create a new REG_DWORD entry called NoDomainUI and set its value to 1. This setting will take effect only after a system reboot. This change will hide the domain drop-down list and force your users to use either their user principal name (e.g., username@domainname) or down-level logon name (e.g., domainnameusername) to log on to Windows.