How Windows NT Uses MS-DOS Configuration Files

During system startup, Windows NT adds any Path, Prompt, and Set commands from the /AUTOEXEC.BAT file to the Windows NT environment variables and then ignores the rest of the contents of /AUTOEXEC.BAT and /CONFIG.SYS. If these files are not present when you install Windows NT, the Setup program creates them.

For a RISC-based computer, default AUTOEXEC.NT and CONFIG.NT files are created.

The path and other Windows NT environment information are stored under the following Registry key:


HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet
\Control\Session Manager\Environment

When an MS-DOS–based application is started, Windows NT executes files specified in the application's PIF or the AUTOEXEC.NT and CONFIG.NT files in the SystemRoot\SYSTEM32 directory. Any changes made in one of these files take effect as soon as the file is saved and a new MS-DOS–based application is started that uses that file. You do not need to restart your system after changing the *.NT files.

File

Use in Windows NT

/AUTOEXEC.BAT

Path and environment variables are added to the Windows NT environment at system startup.

/CONFIG.SYS

Not used by Windows NT.

AUTOEXEC.NT and CONFIG.NT in SystemRoot\SYSTEM32

Used every time an MS-DOS – based application is run with the _DEFAULT.PIF. (Custom *.NT files can be created and used when starting an application from another PIF.)


You can use Windows NT Diagnostics to view the contents of the AUTOEXEC.NT files and the CONFIG.NT files by choosing commands from the File menu. You can edit the contents of these files using any text editor.

Commands in the AUTOEXEC.BAT and CONFIG.SYS files for starting applications and initializing drivers are ignored in Windows NT. If you want an application to run automatically when you start Windows NT, place an icon for the application in the Startup group in Program Manager, as described in Chapter 3, "Program Manager," in the Windows NT System Guide. For a service or driver, use the Services icon in Control Panel to define the startup type. This setting is saved as the Start value in the service's subkey, in the Registry under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services.