"Config.nt The system file is not suitable for running MS-DOS and Microsoft Windows applications" error message when you try to run a program in Windows 2000

This article applies to Windows 2000. Support for Windows 2000 ends on July 13, 2010. The Windows 2000 End-of-Support Solution Center is a starting point for planning your migration strategy from Windows 2000. For more information see the Microsoft Support Lifecycle Policy.


When you try to run a program on a Microsoft Windows 2000-based computer, you may receive the following error message:
config.nt The system file is not suitable for running MS-DOS and Microsoft Windows applications. Choose 'Close' to terminate the application.


This issue may occur if all the following conditions are true:
  • You try to run a 16-bit program.
  • You have installed the MS04-032 Security Update for Microsoft Windows.
  • You have disabled 8.3 file name creation for the NTFS file system.
When you run a 16-bit program on Windows 2000, the program runs in the Microsoft Windows NT Virtual DOS Machine (NTVDM). The NTVDM is a multithreaded process that simulates a 16-bit Windows environment where 16-bit Windows-based programs can be run as separate threads. The NTVDM uses the TMP system variable to find a location to run the program. Typically, the TMP system variable is set to C:\WINNT\Temp. This folder uses the 8.3 file-naming format when new files are created, instead of using long file names.

After the MS04-032 Security Update for Microsoft Windows is installed, the NTVDM uses the TMP user variable instead of the TMP system variable. If 8.3 file name creation is disabled on your computer, the TMP user variable uses long file names.


To work around this issue, follow these steps:
  1. Click Start, point to Settings, and then click Control Panel.
  2. Double-click System, click the Advanced tab, and then click Environment Variables.
  3. In the User variables for User_Name list, click TMP, and then click Edit.
  4. In the Variable value box, type c:\winnt\temp, and then click OK three times.

    Alternatively, type the path of any folder that does not use long file names in the Variable Value box.
  5. Close Control Panel.
Note To work around this issue for many users, you can use the PathMan.exe utility to update the TMP user variable by using a logon script. PathMan.exe is included in the Microsoft Windows 2000 Server Resource Kit. For more information about PathMan.exe, click Tools Help in the Windows 2000 Server Resource Kit, expand Computer Management Tools, and then click PathMan.exe.

More Information

When 8.3 file name creation is disabled, the NtfsDisable8dot3NameCreation registry entry has a value of 1. This registry entry is in the following registry subkey:
Because many 16-bit programs cannot use long file names, we recommend that you do not disable 8.3 file name creation on computers that run 16-bit programs.

For additional information about the MS04-032 Security Update for Microsoft Windows, click the following article number to view the article in the Microsoft Knowledge Base:

840987 MS04-032: Security update for Microsoft Windows


Article ID: 889506 - Last Review: Feb 16, 2017 - Revision: 3