AUTOEXEC.NT Error after Installation of Windows XP SP2

TOPIC

After installation of Service Pack 2, Windows XP may display an error message relating to "AUTOEXEC.NT" when trying to run certain 16-bit applications.

DISCUSSION

Like other applications (e.g. some popular games), the InstallShield software used for the installation of older versions of Amiga Forever (up to version 6.0) makes use of 16-bit Windows technology which requires a valid AUTOEXEC.NT file to be present in the system. This file, which is part of the Windows 16-bit subsystem as it ships with Windows 2000, Windows XP, and Windows Server 2003, normally resides in the "System32" subdirectory of the Windows installation directory.

Installation of Windows XP Service Pack 2 on an otherwise "healthy" Windows XP system may delete the AUTOEXEC.NT file. As a result, when trying to run certain applications which make use of 16-bit technology an error message like the following may be displayed: "16 bit Windows Subsystem - 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."

The error message can be misleading, because it is displayed even if the AUTOEXEC.NT file is actually missing.

To verify whether you have the file, type "%windir%/system32/" in the address bar of an Explorer window. If there is no AUTOEXEC.NT file proceed as follows:

1. Browse to "%windir%/repair/" (usually "C:\WINDOWS\repair")
2. Right-Click and Copy the AUTOEXEC.NT file
3. Browse to "%windir%/system32/" (usually "C:\WINDOWS\System32")
4. Right-Click inside the window and Paste the file

The error condition described here may also be the result of corruption of the AUTOEXEC.NT file, in which case the above procedure may be helpful to restore a valid file.

Corruption of the AUTOEXEC.NT file has also been related to virus programs. You may want to virus-check your system with one of the following free tools:

• Symantec Virus Detection
• Panda ActiveScan

Microsoft has several Knowledge Base articles on this issue, including the following:

• Error message when You Install or Start an MS-DOS or 16-Bit Windows-Based Program
• An Error Message Occurs when You Run an MS-DOS or 16-Bit Windows Program

Please note that Windows Vista and Windows 7 do not include a 16-bit subsystem. The 16-bit components described in this article will not work on Windows Vista or Windows 7.

This condition does not apply to Amiga Forever 2005 and higher, which use a new installer, based on MSI (Windows installer) technology.

Related Links

• "Can't run 16-bit Windows Program" Installation Error