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Q245265: Documentation Error: Disabling the OS/2 Subsystem

Article: Q245265
Product(s): Microsoft Windows NT
Version(s): winnt:4.0
Operating System(s): 
Keyword(s): kbdocfix kbdocerr
Last Modified: 11-JUN-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 
- Microsoft Windows NT Server, Enterprise Edition 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

SUMMARY
=======

The Microsoft Windows NT 4.0 Workstation Resource Kit describes a way to disable
the OS/2 subsystem that does not work.

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

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.

The "To Disable the OS/2 Subsystem in Windows NT" topic (on page 910) in the
Windows NT 4.0 Workstation Resource Kit contains the following information:

  In Registry Editor, change the value of GlobalFlag to 20100000 in the
  following registry path:

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SessionManager

This information is not correct. In versions of Windows NT up to version 3.51,
you can use the GlobalFlag value as described above to disable the OS/2
subsystem in the following key:

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager

Note the difference between "SessionManager" and "Session Manager."

To disable any subsystem other than Win32 (for example, OS/2 or POSIX) in Windows
NT 4.0, you can use the "dosonly" command in the Config.nt file in the
%SystemRoot%\System32 folder. The comment area of the Config.nt file contains
these instructions:

  DOSONLY
  By default, you can start any type of application when running Command.com. If
  you start an application other than an MS-DOS-based application, any running
  TSR may be disrupted. To ensure that only MS-DOS-based applications can be
  started, add the command dosonly to Config.nt or other startup file.

Additional query words: os2

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Keywords          : kbdocfix kbdocerr 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400search kbWinNTS400
Version           : winnt:4.0
Issue type        : kbinfo

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