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Q236414: Cannot Use Shares with LMCompatibilityLevel set to Only NTLM 2

Article: Q236414
Product(s): Microsoft Windows NT
Version(s): winnt:4.0 SP4,4.0 SP5
Operating System(s): 
Keyword(s): 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 versions 4.0 SP4, 4.0 SP5 
- Microsoft Windows NT Workstation versions 4.0 SP4, 4.0 SP5 
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SYMPTOMS
========

After you change the type of authentication to use only NTLM version 2, shares
may not be accessible on other computers.

CAUSE
=====

Starting in Windows NT 4.0 Service Pack 4 (SP4), Microsoft provided an
enhancement to control the type of security used for authentication using
NTLMSSP. A new registry key named LMCompatibilityLevel was added. With the key
set to "Allow only NTLMv2", the local RDR does not succeed in getting
credentials.

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

For additional information about LMCompatibility settings, please click the
article number below to view the article in the Microsoft Knowledge Base:

  Q147706 How to Disable LM Authentication on Windows NT

Because of the increased security level, the NET USE command may not work when
the domain is defaulted. This is because the defaulted or non-existent domain is
rejected at this security level. For this command to work the domain name must
be supplied.


Additional query words:

======================================================================
Keywords          : kbWinNT4sp6fix 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400search kbWinNT400search kbWinNTW400sp5 kbWinNTW400sp4 kbWinNTSsearch kbWinNTS400sp5 kbWinNTS400sp4 kbWinNTS400search kbNTTermServ400 kbNTTermServSearch
Version           : winnt:4.0 SP4,4.0 SP5
Hardware          : ALPHA x86
Issue type        : kbbug
Solution Type     : kbfix

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