DOCUMENT:Q140515  08-AUG-2001  [winnt]
TITLE   :BUG: VDM Apps Can Cause Other Applications to Redraw Slowly
PRODUCT :Microsoft Windows NT
PROD/VER:3.51
OPER/SYS:
KEYWORDS:kbbuglist

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The information in this article applies to:

 - Microsoft Windows NT Workstation version 3.51 
 - Microsoft Windows NT Server version 3.51 
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SYMPTOMS
========

On WinNT 3.51, moving a VDM Application on the screen or changing its focus in
relation to other 16-bit or 32-bit Windows-based applications (moving to the
foreground or background) causes the Windows-based applications to redraw slowly
taking four to six seconds.

CAUSE
=====

Some VDM applications, such as Microsoft QuickBasic applications or Edit.com
with the menu pulled down, have a thread that loops tightly while waiting for
keyboard input. This thread, always being in the run/ready state, slows the
redraw of other Windows-based applications.

WORKAROUND
==========

This problem can be eliminated by creating a .pif file for the VDM Application
using Pifedit.exe. Click the Advanced button, and reduce its Foreground and
Background Priority by half.

STATUS
======

Microsoft has confirmed this to be a problem in Windows NT version 3.51. We are
researching this problem and will post new information here in the Microsoft
Knowledge Base as it becomes available.

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Keywords          :  kbbuglist
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNT351search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS351 kbWinNTS351search
Version           : 3.51

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