How to Prevent Windows from Loading the Optional OS/2 and POSIX Subsystems (320869)


The information in this article applies to:

  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Professional
This article was previously published under Q320869
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:

256986 Description of the Microsoft Windows Registry

SUMMARY

In some cases, you may want to make sure that the Microsoft Windows 2000 session manager (SMSS) does not load any optional subsystems, such as OS/2 or POSIX. This article describes how to do this.

MORE INFORMATION

To prevent Windows 2000 from loading the optional subsystem components, follow these steps.

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.
  1. Click Start, and then click Run.
  2. In the Open box, type regedt32, and then click OK.

    IMPORTANT NOTE: Because of differences in the way that Regedit.exe and Regedt32.exe handle the registry, do not use Regedit.exe for this procedure. For more information about Regedit.exe and Regedt32.exe, see the link at the end of the "More Information" section. If you use Regedit.exe and problems result, restart your computer, and then use the last known good configuration to recover.
  3. Locate the following registry subkey:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\SubSystems

  4. On the Registry menu, click Save Key.
  5. In the File name box, type subsystems_key, and then click Save Key.

    NOTE: If you later have to restore this registry key, open Regedt32.exe, click the SubSystems key, and then click Restore on the Registry menu. Locate the file that you just saved, click it, click Open, and then click Yes.
  6. In the right pane of the Registry Editor window, double-click the Optional:REG_MULTI_SZ:Os2 Posix... line.

    The Multi-String Editor opens.
  7. Press the DELETE key to delete all the data in this window.
  8. Click OK.

    OS/2 POSIX no longer appears next to Optional: REG_MULTI_SZ in the right pane of the Registry Editor window.
  9. Quit Registry Editor.
  10. Restart the computer.

    NOTE: You do not have to remove the OS2 or POSIX specific system files or delete other OS2 or POSIX specific registry keys values.
For additional information about Regedit.exe and Regedt32.exe, click the article number below to view the article in the Microsoft Knowledge Base:

155267 Registry Editors Installed by Windows NT 4.0

Modification Type:MajorLast Reviewed:11/19/2003
Keywords:kbinfo KB320869
©2003 Microsoft Corporation. All rights reserved.