Software Restriction Policies Do Not Recognize 16-Bit Programs (319458)

The information in this article applies to:

Microsoft Windows XP Home Edition
Microsoft Windows XP Professional

This article was previously published under Q319458

SYMPTOMS

If you configure a Software Restriction policy to restrict access to a 16-bit program such as Command.com or Edit.com, users can still start the program even though they are not permitted to run it.

CAUSE

Commands that run in the Virtual DOS Machine (Ntvdm.exe) are not recognized by Software Restriction policies.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows XP. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

322389 How to Obtain the Latest Windows XP Service Pack

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

   Date         Time   Version      Size     File name
   ------------------------------------------------------
   09-Apr-2002  00:50  5.1.2600.42  898,560  Kernel32.dll

WORKAROUND

To work around this problem, restrict access to Ntvdm.exe by using access control lists (ACLs) at the file-system level. Note that using this method blocks all 16-bit code.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows XP Service Pack 1.

MORE INFORMATION

Note that you cannot use Software Restriction policies to prevent code from being run outside the Win32 subsystem. For example, user can run the same command from the POSIX subsystem. For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

101270 Disabling the POSIX Subsystem

Modification Type:	Minor	Last Reviewed:	9/27/2005
Keywords:	kbHotfixServer kbQFE kbbug kbfix kbSecurity kbWinXPsp1fix KB319458