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Q255671: Unlocking Workstation with Invalid Password Increments Twice

Article: Q255671
Product(s): Microsoft Windows NT
Version(s): winnt:4.0 SP4,4.0 SP5,4.0 SP6,4.0 SP6a
Operating System(s): 
Keyword(s): kbWinNT400PreSP7Fix
Last Modified: 08-MAY-2002

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The information in this article applies to:

- Microsoft Windows NT Server versions 4.0 SP4, 4.0 SP5, 4.0 SP6, 4.0 SP6a 
- Microsoft Windows NT Workstation versions 4.0 SP4, 4.0 SP5, 4.0 SP6, 4.0 SP6a 
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SYMPTOMS
========

After you apply Windows NT 4.0 Service Pack 4 to a workstation or server,
attempts to unlock the computer by using a valid user name and an invalid
password can cause the account lockout count for the account being used to be
incremented by two.

CAUSE
=====

A new registry key was added in Service Pack 4 to confirm that a valid password
is used against a domain controller rather than the local computer's credentials
cache. When this is enabled, attempting to unlock the computer by using an
invalid password causes the password to be validated twice against a domain
controller, causing the account lockout count to be incremented twice.

The registry key is:

  HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\ForceUnlockLogon

For additional information about this key, click the article number below to view
the article in the Microsoft Knowledge Base:

  Q188700 Screensaver Password Works Even if Account Is Locked Out

RESOLUTION
==========

A supported fix is now available from Microsoft, but it is only intended to
correct the problem described in this article and should be applied only to
systems experiencing this specific problem. This fix may receive additional
testing at a later time, to further ensure product quality. Therefore, if you
are not severely affected by this problem, Microsoft recommends that you wait
for the next Windows NT 4.0 service pack that contains this fix.

To resolve this problem immediately, contact Microsoft Product Support Services
to obtain the fix. For a complete list of Microsoft Product Support Services
phone numbers and information about support costs, please go to the following
address on the World Wide Web:

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

NOTE: In special cases, charges that are normally incurred for support calls may
be canceled, if a Microsoft Support Professional determines that a specific
update will resolve your problem. Normal support costs will apply to additional
support questions and issues that do not qualify for the specific update in
question.

The English version of this fix should have the following file attributes or
later:

  Date        Time                Size    File name     Platform
  --------------------------------------------------------------
  24/02/2000  02:33              124,176  Msgina.dll    Intel



STATUS
======

Microsoft has confirmed this to be a problem in the Microsoft products that are
listed at the beginning of this article.

Additional query words:

======================================================================
Keywords          : kbWinNT400PreSP7Fix 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400search kbWinNT400search kbWinNTW400sp5 kbWinNTW400sp4 kbWinNTSsearch kbWinNTS400sp6 kbWinNTS400sp5 kbWinNTS400sp4 kbWinNTS400search kbWinNTW400sp6 kbWinNTW400SP6a
Version           : winnt:4.0 SP4,4.0 SP5,4.0 SP6,4.0 SP6a
Hardware          : ALPHA x86
Issue type        : kbbug
Solution Type     : kbfix

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