AUTOEXEC.BAT

AUTOEXEC.BAT loads and executes after COMMAND.COM. AUTOEXEC.BAT is an important ASCII file that loads files and programs required by peripherals and applications and sets up the user's desired environment variables. The content of this file is usually established by writes during the installation of some peripheral or software (including DOS and Windows); but the file can easily be changed by the user to customize his or her system. Each additional hardware or software installation may increase the contents of this file.

Each line is actually a command that is processed by COMMAND.COM (which is why COMMAND.COM must load first), and each line can be separately entered from the command prompt. A simple system running small simple programs may not need AUTOEXEC.BAT.

CAUTION: Make a backup copy of AUTOEXEC.BAT before making changes. This makes it easier to restore the original copy in case any problems occur.

System or peripheral failures can start in the AUTOEXEC.BAT when program loads into memory. This is not actually a AUTOEXEC.BAT problem but an installation problem with the installed software or peripheral. AUTOEXEC.BAT is the first place to look for statements that load TSRs (Terminate and Stay Resident programs). If the user gets an 'OUT OF MEMORY' error message, suspect TSRs as a possibility.

Troubleshoot for this problem in AUTOEXEC.BAT by editing the file and inserting a semicolon at the beginning of any suspect lines. When the computer reboots, it will ignore the line with the semicolon (treating it as a comment) and not load the specified TSR or program. Alternatively, press SHIFT+F8 during the boot (just after the memory check when the 'Starting Windows 95' message appears), to confirm or skip the execution of each consecutive line of the AUTOEXEC.BAT. This way a user can try to stop the possibly offending load statement without actually editing the AUTOEXEC.BAT file.