A contraction of Automatically Executed Batch. A special MS-DOS batch file, located in the root directory of the startup disk, that runs automatically every time you start or restart your computer. The commands contained in AUTOEXEC.BAT are executed one by one, just as if you typed them at the system prompt. An AUTOEXEC.BAT file can be used to load hardware device drivers, set the system prompt, change the default drive to the first network drive, and log the user in to the file server.
In OS/2, you can select any batch file to be used as AUTOEXEC.BAT for a specific MS-DOS session, so you can tailor specific environments for separate MS-DOS sessions, each using a different AUTOEXEC.BAT file.
See also AUTOEXEC.NCF; boot; bootstrap; CONFIG.SYS.