The Windows Autoexec.bat file is a text-based batch script that is executed by the operating system at boot time. It stands for “automatically executed batch file”.
This script generally contains two commands: one to load any programs that you want to run automatically on every boot, and another to call the Windows environment for initialization. The command “autoexec” or “autocheck” then executes a set of user configurations.
The Autoexec.bat file may also be used to load DOS programs in a similar manner to the way these are executed using a shortcut icon in Windows 9x and ME, or association with a program in Windows NT or later.
In this case, the Autoexec.bat file must contain either a start command for the associated DOS program or a line pointing it at another batch file from which it can obtain such a command. This practice is no longer widely employed except when running legacy applications under emulation software such as DOSBox since the standardization of shortcuts that launch directly into a predefined directory containing an executable to run has become prevalent among users and application developers.
In order for commands contained in Autoexec files to actually execute when the operating system boots up, the file must be added to a special list in the Windows Registry. The autoexec.bat file does not actually exist on disk at this point in time because it is located in the registry and not on disk so any errors in the code will not show up when you run it manually.
If you want to create one yourself in order to test out your DOS commands before you try them in your real boot process then I suggest making a copy of another Autoexec which is similar to what you are trying to achieve and then rename that copy with “.old” for backup or .bak”.