Error message when you install or start an MS-DOS or 16-bit Windows-based program

16-bit MS-DOS Subsystem
path to the program that you are trying to start or install
C:\Winnt\System32\config.nt The system file is not suitable for running MS-DOS and Microsoft Windows applications. Choose 'Close' to terminate the application.

16-bit MS-DOS Subsystem
path to the program that you are trying to start or install
config.nt The system file is not suitable for running MS-DOS and Microsoft Windows applications. Choose 'Close' to terminate the application. 

16-bit MS-DOS Subsystem
path to the program that you are trying to start or install
C:\Windows\System32\Autoexec.nt The system file is not suitable for running MS-DOS and Microsoft Windows applications. Choose 'Close' to terminate the application. 

Although you may be prompted to quit the program or ignore the error message, either selection makes the program quit. 

To resolve this issue, use one of the following methods.
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Method 1

   1. Insert the CD into the CD drive or DVD drive.
   2. Click Start, and then click Run.
   3. In the Open box, type cmd, and then click OK.
   4. At the command prompt, type the following commands, pressing ENTER after each command:

      expand CD-ROM Drive Letter:\i386\config.nt_ c:\windows\system32\config.nt
      expand CD-ROM Drive Letter:\i386\autoexec.nt_ c:\windows\system32\autoexec.nt
      expand CD-ROM Drive Letter:\i386\command.co_ c:\windows\system32\command.com
      exit
   5. Start or install the program. If the issue is resolved, do not complete the remaining steps. If the issue is not resolved, go to the next step.
   6. Note: The Command.com file is not edited or created in the following process. Because of this, you may have to expand it from your Windows XP CD-ROM.

      Start Notepad.
   7. In Notepad, type the following entries:

         dos=high, umb
      device=%SYSTEMROOT%\system32\himem.sys
      files=40

   8. On the File menu, click Save As.
   9. In the File Name box, type Config.nt, and then click Save. Close the Config.nt file.
  10. On the File menu, click New.
  11. In the new blank document, type the following entries:

      @echo off
          lh %SYSTEMROOT%\system32\mscdexnt.exe
          lh %SYSTEMROOT%\system32\redir
          lh %SYSTEMROOT%\system32\dosx
          SET BLASTER=A220 I5 D1 P330 T3

  12. On the File menu, click Save As.
  13. In the File Name box, type Autoexec.nt, and then click Save. Close the Autoexec.nt file.
  14. Start Windows Explorer. Locate the Config.nt file, right-click the Config.nt file, and then click Copy.
  15. Right-click the %SYSTEMROOT%\System32 folder, and then click Paste.
  16. Locate the Autoexec.nt file, right-click the Autoexec.nt file, and then click Copy.
  17. Right-click the %SYSTEMROOT%\System32 folder, and then click Paste.
  18. Locate the Command.com file, right-click the expanded Command.com file, and then click Copy.
  19. Right-click the %SYSTEMROOT%\System32 folder, and then click Paste. Restart your computer.

If the issue continues to occur, copy the Autoexec.nt and Config.nt files from the Repair folder in Windows to the System folder. To do so, follow these steps:

   1. Click Start, click Run, type c:\windows\repair, and then click OK.
   2. Right-click Autoexec.nt, and then click Copy.
   3. Click Start, click Run, type c:\windows\system32, and then click OK.
   4. Right-click anywhere in that folder, and then click Paste.
   5. Right-click the Autoexec.nt file that you just copied, and then click Properties.
   6. Click to select Read-Only, and then click OK.
   7. Repeat steps 1 through 6 to copy the Config.nt file.

Note You must enable Read-Only permissions or the files will be removed after you restart Windows.
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Method 2

   1. Click Start, click Run, type C:\windows\repair, and then click OK.
   2. Right-click the Autoexec.nt file, and then click Copy.
   3. Click Start, click Run, type %windir%\system32, and then click OK.
   4. In the System32 folder, press Ctrl + V to paste the Autoexec.nt file in this folder.