KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q149215: VB 4.0 Apps Can Only Be Scheduled Using System Account

Article: Q149215
Product(s): Microsoft Windows NT
Version(s): 3.5,3.51,4.0
Operating System(s): 
Keyword(s): kbenv
Last Modified: 20-FEB-2002

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

- Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0 
- Microsoft Windows NT Server versions 3.5, 3.51, 4.0 
-------------------------------------------------------------------------------


SUMMARY
=======

When you run a Microsoft Visual Basic 4.0 application using the AT Scheduler
service, if the service is configured to use any account other than the system
user account, the application will quit, and in Windows NT 3.51 get the
following error:

  Unexpected error, quitting

Under Windows NT 4.0, you will get the following error:

  Application error caused a Stack Fault in Module <unknown> 00c7:4394f
  will close.

CAUSE
=====

Windows applications can be scheduled to run interactively only if the Scheduler
service is running under the system user account (the default account). If you
reconfigure the Scheduler service to run using any other account, including
administrator accounts, then Windows applications cannot be scheduled to run
fully interactively (that is, they cannot make use of the screen and keyboard).
This apparent limitation is designed to avoid possible security issues.

If you attempt to schedule a Microsoft Visual Basic 4.0 application under any
account other than the system account, the VB runtime DLL VB40032.dll will cause
a memory access violation because it does not have access rights to some desktop
resources.

NOTE: If you try to run a VB4 application with scheduler under Windows NT 4.00,
you will get the following error regardless of whether you have scheduler setup
for the /INTERACTIVE switch and "Allow Service To Interact With Desktop":

  Application Error
  Caused a Stack Fault in Module <unknown>00c7:4394|||will close

For additional information on this error, please see the following article in the
Microsoft Knowledge Base:

  ARTICLE-ID: Q156735
  TITLE : WOW Applications Stack Fault When Launched by a Service


NOTE: If you schedule a VB5 application it will work fine with system account or
a specific user's account (necessary for network access)

WORKAROUND
==========

To get a VB 4.0 application to run under the scheduler service using Windows NT
3.51, do the following:

1. Ensure that the Scheduler service is configured to run using the system
  account. To do this, select the Services tool under Control Panel. From the
  list of services, select Schedule and click the Startup button. Make sure
  that you click the Log On As System Account button.

2. When you schedule the application using the AT command line, make sure you
  include the interactive switch.


Additional query words:

======================================================================
Keywords          : kbenv 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS350 kbWinNTS351search kbWinNTS350search
Version           : :3.5,3.51,4.0
Hardware          : ALPHA x86

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

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.