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Q241338: Windows NT Lan Manager 3 Logon Prevents Other Logon Activity

Article: Q241338
Product(s): Microsoft Windows NT
Version(s): winnt:4.0
Operating System(s): 
Keyword(s): kberrmsg kbnetwork kbWinNT4sp6fix
Last Modified: 20-MAY-2002

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The information in this article applies to:

- Microsoft Windows NT Server version 4.0, Terminal Server Edition 
- Microsoft Windows NT Server version 4.0 
- Microsoft Windows NT Workstation version 4.0 
- Microsoft Windows NT Server, Enterprise Edition version 4.0 
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SYMPTOMS
========

When a client uses Windows NT LAN Manager version 2 authentication (also known
as NTLMv2) that is configured with the LmCompatibilityLevel setting to 3 or
higher to make a connection to a server running Windows NT 4.0 before a console
user has logged on interactively or some other client has performed network
logon using LAN Manager or NTLMv1 authentication, one of the following symptoms
may occur on the server:

- The server may generate an "access violation" error message, possibly
  relating to the LSASS service. This may occur on both the server and the
  client during startup, especially during periods of heavy network logon
  traffic.

- The domain name field may not appear on the logon screen of the server even
  though the user name and password fields do. You may not be able to log on to
  the domain because this indicates that the domain controller cannot be found.

- Your logon attempt may not work, and you may receive the following error
  message:

  The system cannot log you on (C0000037). Please try again or consult your
  system administrator.

CAUSE
=====

This behavior occurs because the Windows NT LAN Manager version 2 (level 3+)
logon is received and processed by the server before the NlSamInitialize
function is called, causing an "Access violation" error message. Also, at this
time Lsass.exe generates a "STATUS_PORT_DISCONNECTED" error message, which
prevents subsequent logon attempts from succeeding.

RESOLUTION
==========

Windows NT Server or Workstation 4.0
------------------------------------

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the
individual software update. For information on obtaining the latest service
pack, please go to:

- http://www.microsoft.com/Windows/ServicePacks/

-or-

- Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

For information on obtaining the individual software update, contact Microsoft
Product Support Services. For a complete list of Microsoft Product Support
Services phone numbers and information on support costs, please go to the
following address on the World Wide Web:

  http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS


Windows NT Server 4.0, Terminal Server Edition
----------------------------------------------

To resolve this problem, obtain the latest service pack for Windows NT Server
4.0, Terminal Server Edition. For additional information, please see the
following article in the Microsoft Knowledge Base:

  Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack


STATUS
======

Microsoft has confirmed this to be a problem in Windows NT 4.0 and Windows NT
Server 4.0, Terminal Server Edition.

This problem was first corrected in Windows NT Server 4.0 Service Pack 6 and
Windows NT Server 4.0, Terminal Server Edition Service Pack 6.

MORE INFORMATION
================

Windows NT 4.0 supports Windows NT challenge/response (or Windows NT LAN Manager
challenge/response) as a method of authentication, along with Basic
Authentication and Anonymous Access. Microsoft has developed an enhancement to
NTLM called Windows NT LAN Manager version 2 which uses a 128-bit
password-derived key and significantly improves session security mechanisms.

For more information about Windows NT LAN Manager version 2, please click the
article number below to view the article in the Microsoft Knowledge Base:

  Q147706 How to Disable LM Authentication on Windows NT

This behavior may not occur when the following situations circumvent the issues
involved:

- When a server service that runs using a user account starts before the first
  non-anonymous logon.

- When a user interactively logs on to the server console before the first
  non-anonymous logon occurred.

- When a client computer is not configured to send Windows NT LAN Manager
  version 2 only (level 3) as the first non-anonymous logon


Additional query words: ntlmv2 ntlm invalid handle invalid_handle 6

======================================================================
Keywords          : kberrmsg kbnetwork kbWinNT4sp6fix 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400search kbWinNTS400 kbNTTermServ400 kbNTTermServSearch
Version           : winnt:4.0
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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