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Q159971: SetTimer() API Causes Memory Leak in the WOW Subsystem

Article: Q159971
Product(s): Microsoft Windows NT
Version(s): winnt:4.0
Operating System(s): 
Keyword(s): kbProgramming
Last Modified: 09-AUG-2001

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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 
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SYMPTOMS
========

When you run 16-bit applications, such as Microsoft Project 4.0, Microsoft Mail
3.0, or Schedule+ 1.0, which frequently call the SetTimer() API, the system may
run out of memory resulting in poor performance and very sluggish response.

The following error message may also appear:

  System Process - Out of Virtual Memory

  Your system is running low on virtual memory. Please close some applications.
  You can then start the System option in the Control Panel and choose the
  Virtual Machine button to create an additional page file or to increase the
  size of your current paging file.

CAUSE
=====

The SetTimer API causes a memory leak in the Windows on Windows (WOW) subsystem.
A memory leak is caused by an application or process that allocates memory for
use, but does not later free it up when done. The result is that available
memory is completely used up over time, often causing the system to stop
functioning properly.

STATUS
======

Microsoft has confirmed this to be a problem in Windows NT version 4.0. This
problem was corrected in the latest Microsoft Windows NT 4.0 U.S. Service Pack.
For information on obtaining the service pack, query on the following word in
the Microsoft Knowledge Base (without the spaces):

  S E R V P A C K


Additional query words: prodnt wow

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Keywords          : kbProgramming 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400
Version           : winnt:4.0

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