KB159969 - AutoLogon Fails If DontDisplayLastUserName Is Also Enabled

Article ID: 159969

Article Last Modified on 11/1/2006

Microsoft Windows NT Workstation 3.5
Microsoft Windows NT Workstation 3.51
Microsoft Windows NT Workstation 4.0 Developer Edition
Microsoft Windows NT Server 3.5
Microsoft Windows NT Server 3.51
Microsoft Windows NT Server 4.0 Standard Edition

This article was previously published under Q159969

SYMPTOMS

Although you have the AutoLogon feature of Windows NT enabled, when you start your Windows NT system you may receive the following error message instead of being automatically logged onto the computer:

Logon Message
The system could not log you on. Make sure your User name and domain are correct, then type your password again. Letters in passwords must be typed using the correct case. Make sure that Caps Lock is not accidentally on.

When you click OK, you are prompted for a user name and password that is valid for the system.

CAUSE

Your Windows NT system also has the registry entry DontDisplayLastUserName enabled.

RESOLUTION

To resolve this issue and use the AutoLogon feature, you will need to disable DontDisplayLastUserName using the following steps:

WARNING: Using Registry Editor incorrectly may cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

Start Registry Editor (Regedt32.exe) and select the following subkey:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion \Winlog
Select the DontDisplayLastUserName value, and then click String from the Edit menu.
Type 0 in the String Editor dialog box, and then click OK.
Exit Registry Editor and restart your Windows NT computer.

MORE INFORMATION

The reason for this conflict is that the registry values are mutually exclusive. If you enable the DontDisplayLastUserName, you are effectively blanking out the user name during authentication. Auditing Logon and Logoff Success and Failure Events demonstrates that the user name is not available to the system:

11/11/96 2:41:02 PM  Security Failure Audit  Logon/Logoff   529   NT
AUTHORITY\SYSTEM  <Servername> Logon Failure:
      Reason: Unknown user name or bad password
      User Name:
      Domain: <Domain>
      Logon Type: 2
      Logon Process: User32
      Authentication Package: MICROSOFT_AUTHENTICATION_PACKAGE_V1_0
      Workstation Name: <Servername>

NOTE: The User Name field is blank. When the user name is not suppressed in the registry, any other circumstance to cause a failed logon attempt always displays the user name attempting to logon. This includes gibberish for either a DefaultUserName or DefaultPassword. In these cases the user name field is occupied.

For additional information, please see the following article in the Microsoft Knowledge Base:

ARTICLE-ID: 97597
TITLE : How to Enable Automatic Logon in Windows NT

Additional query words: prodnt Auto autoadminlogon

Keywords: kbenv kbinfo KB159969