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Q258837: Services That Use Remote Connections Leak User Sessions

Article: Q258837
Product(s): Microsoft Windows NT
Version(s): 4.0
Operating System(s): 
Keyword(s): kbWinNT400PreSP7Fix
Last Modified: 06-AUG-2002

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The information in this article applies to:

- Microsoft Windows NT Workstation version 4.0 
- Microsoft Windows NT Server version 4.0 
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IMPORTANT: This article contains information about modifying the registry. Before you 
modify the registry, make sure to back it up and make sure that you understand how to restore 
the registry if a problem occurs. For information about how to back up, restore, and edit the 
registry, click the following article number to view the article in the Microsoft Knowledge Base:

  Q256986 Description of the Microsoft Windows Registry

SYMPTOMS
========

When you run multiple services that connect to the Server service on a remote
computer (for example, by using named pipes or to access files) and the services
are using a user account for the services, under certain circumstances user
logons that are created by the services will be left open on the server. These
sessions continue to contribute to the active session count on the server, and
may cause the server to reach the limit of 10 authenticated connections on
Microsoft Windows NT Workstation or the license limit on Microsoft Windows NT
Server when you are running in Per-Server licensing mode.

When this occurs, programs receive error code 71 or 1395 when they make a new
connection to the server.

CAUSE
=====

The Windows NT redirector does not log a user off when a service is stopped when
the session is going idle. The redirector relies on the removal of the session
by a scavenger routine. This routine does not disconnect if the session is
reused in the meantime.

RESOLUTION
==========

WARNING: If you use Registry Editor incorrectly, you may cause serious problems
that may require you to reinstall your operating system. Microsoft cannot
guarantee that you can solve problems that result from using Registry Editor
incorrectly. Use Registry Editor at your own risk.

A supported fix is now available from Microsoft, but it is only intended to
correct the problem that is described in this article. Apply it only to
computers that are experiencing this specific problem. This fix may receive
additional testing. 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, visit the following Microsoft
Web site:

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

NOTE: In special cases, charges that are ordinarily incurred for support calls
may be canceled if a Microsoft Support Professional determines that a specific
update will resolve your problem. The typical 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    Version        Size     File name   Platform
  ------------------------------------------------------------------
  05/12/2000  05:29p  4.0.1381.7052  265,264  Rdr.sys     Intel
  05/16/2000  04:55p  4.0.1381.7052   58,640  Wkssvc.dll  Intel



To enable this fix, you must install the hotfix files and set a registry entry as
follows:

1. Start Registry Editor (Regedt32.exe).

2. Locate the following key in the registry:

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters

3. On the Edit menu, click Add Value, and then add the following registry value:

  Value Name: KeepConn
  Data Type: REG_DWORD
  Value: 0

4. Quit Registry Editor.

WORKAROUND
==========

You can disconnect the client computer sessions by using the net session /delete
<computer_name> command. This disconnects all logons from that computer
and closes all open files. Note that using this command can cause data loss if
open files that have not been saved are closed.

You can also use a program to use the NetSessionEnum and NetSessionDel functions
to find and remove client sessions.

STATUS
======

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

Additional query words:

======================================================================
Keywords          : kbWinNT400PreSP7Fix 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400
Version           : :4.0
Hardware          : ALPHA x86
Issue type        : kbbug
Solution Type     : kbfix

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