Article ID: 103656 - Last Review: February 20, 2007 - Revision: 2.2

Troubleshooting 16-Bit Windows Applications

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This article was previously published under Q103656

For a Microsoft Windows XP version of this article, see 314495 (http://support.microsoft.com/kb/314495/EN-US/ ) .
Many different 16-bit applications designed to run under Windows 3.1 have been tested with Windows NT and later. When you are troubleshooting a 16-bit Windows-based application that is not working properly under Windows NT and later, the following items should be taken into consideration:

If possible, verify that the application works correctly under Windows 3.0 and 3.1.
If the application requires a VxD (virtual device driver), it will not work properly under Windows.
If the application requires Windows 3.0 or 3.1 to be running in 386 enhanced mode, the application will not function properly on either the DEC Alpha or MIPS versions of Windows at this time because these platforms currently emulate only the Intel 80286 architecture.
Check Print Manager to see that a default printer has been selected. Some applications (such as Microsoft Word version 2.0 for Windows) will not function properly under Windows unless a default printer has been selected.
Make sure that any dynamic link libraries (DLLs) used by the application are both current and locatable by the application (either on the system path or explicitly defined within the application or working directory.)

Make sure that the default items in the CONFIG.NT and AUTOEXEC.NT files are present and in the proper order.

In Windows NT 3.1, CONFIG.NT contains the following commands by default:

      files=50
      lastdrive=k
      fcbs=4,0
      dos=high, umb
      device=%SystemRoot%\system32\himem.sys

In Windows NT 3.51 and later, the CONFIG.NT contains the following commands by default:

      dos=high, umb
      device=%SystemRoot%\system32\himem.sys
      files=20

AUTOEXEC.NT contains the following commands by default:

      @echo off
      lh %SystemRoot%\system32\mscdexnt.exe
      lh %SystemRoot%\system32\redir
      lh %SystemRoot%\system32\dosx

Any environment variables required by the Windows-based application should be in the AUTOEXEC.BAT file; if they are, Windows will use them appropriately.

Note that if any changes are made to variables related to the Windows 3.0 or 3.1 subsystem (WOWEXEC.EXE), the user may have to restart the computer in order for these changes to be implemented.
Determine whether Windows has been installed as a stand-alone operating system or as an upgrade of a previous Windows 3.0 or 3.1 installation. If it is an upgrade, information from the WIN.INI and/or SYSTEM.INI files may have not been correctly copied into the Windows Registry database.

To correct this problem, you may have to either migrate these settings again, or reinstall the application that is not working.

For help with migrating application information into the Windows Registry, query on the following reference words in the Microsoft Knowledge Base:
migrate and WIN.INI
Try running the application in a separate memory space by editing the icon or shortcut's properties and checking the appropriate checkbox.