Q86181: Programs with Reserved Windows Filenames May Not Run

Article: Q86181
Product(s): Microsoft Windows 95.x Retail Product
Version(s): WINDOWS:3.1,3.11
Operating System(s): 
Keyword(s): 
Last Modified: 29-AUG-2001

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows versions 3.1, 3.11 
-------------------------------------------------------------------------------

SUMMARY
=======

In Microsoft Windows version 3.1, if a program's executable filename is a name
that is reserved by Windows, the file will not run. There is no error message
associated with this behavior.

In addition, if a program's executable file has a name that is already running in
memory and the program running in memory can only occur once, the duplicate
program will:

- not execute

- not return an error message

- may execute the duplicate program

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

This occurs because when Windows gets the request to run a new program, it
checks for another occurrence of this program in memory. It does this by looking
at the first eight characters of the filename and then comparing the information
to the programs in memory.

If Windows finds another version of this program in memory, it sends this new
instance to the currently running program. It is then up to this program whether
or not to execute a new instance. If the program is set up to make itself
active, then it will become active. If the program is reserved by Windows or its
operating system, such as KERNEL.EXE, then the new program will not execute.

Unusable executable filenames:

  CGA40WOA.EXE
  COMM.EXE
  COMMDLG.EXE
  GDI.EXE
  DISPLAY.EXE
  DOSAPP.EXE
  FIXFONTS.EXE
  FONTS.EXE
  KERNEL.EXE
  KEYBOARD.EXE
  MMSYSTEM.EXE
  MOUSE.EXE
  PROGMAN.EXE
  SHELL.EXE
  USER.EXE

There may be other executable filenames that cannot be duplicated, depending on
the configuration and third-party applications.

KBCategory: kbother kbdisplay kbprb
KBSubcategory: win31

Additional query words: 3.10 3.11 file name

======================================================================
Keywords          :  
Technology        : kbWin3xSearch kbZNotKeyword3 kbWin310 kbWin311
Version           : WINDOWS:3.1,3.11

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.