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 ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Workstation version 3.51 - Microsoft Windows NT Server version 3.51 ------------------------------------------------------------------------------- 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. ====================================================================== Keywords : kbbuglist Technology : kbWinNTsearch kbWinNTWsearch kbWinNT351search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS351 kbWinNTS351search Version : 3.51 ============================================================================= 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 2001.