Editing AUTOEXEC.BAT (section)

==Example==
In early versions of DOS, <code>AUTOEXEC.BAT</code> was by default very simple. The <code>[[DATE (command)|DATE]]</code> and <code>[[TIME (command)|TIME]]</code> commands were necessary as early [[IBM Personal Computer|PC]] and [[IBM Personal Computer XT|XT]] class machines did not have a battery backed-up [[real-time clock]] as default.

<syntaxhighlight lang="dosbatch">
@ECHO OFF
CLS
DATE
TIME
VER
</syntaxhighlight>

In non-US environments, the keyboard driver (like <code>KEYB FR</code> for the French keyboard) was also included. Later versions were often much expanded with numerous third-party device drivers. The following is a basic DOS 5 type <code>AUTOEXEC.BAT</code> configuration, consisting only of essential commands:

<syntaxhighlight lang="dosbatch">
@ECHO OFF
PROMPT $P$G
PATH C:\DOS;C:\WINDOWS
SET TEMP=C:\TEMP
SET BLASTER=A220 I7 D1 T2
LH SMARTDRV.EXE
LH DOSKEY
LH MOUSE.COM /Y
</syntaxhighlight>

This configuration sets common environment variables, loads a disk cache, places common directories into the default [[PATH (DOS command)|PATH]], and initializes the DOS mouse / keyboard drivers. The <code>[[PROMPT (DOS command)|PROMPT]]</code> command sets the [[prompt (computing)|prompt]] to "C:\>" (when the [[working directory]] is the root of the C drive) instead of simply "C>" (the default prompt, indicating only the working drive and not the directory therein).

In general, device drivers were loaded in <code>CONFIG.SYS</code>, and programs were loaded in the <code>AUTOEXEC.BAT</code> file. Some devices, such as mice, could be loaded either as a device driver in <code>CONFIG.SYS</code>, or as a [[Terminate-and-stay-resident program|TSR]] in <code>AUTOEXEC.BAT</code>, depending upon the manufacturer.<ref name="Microsoft_96706"/>

In [[MS-DOS 6.0]] and higher, a DOS boot menu is configurable. This can be of great help to users who wish to have optimized boot configurations for various programs, such as DOS games and Windows.

<syntaxhighlight lang="dosbatch">
@ECHO OFF
PROMPT $P$G
PATH C:\DOS;C:\WINDOWS
SET TEMP=C:\TEMP
SET BLASTER=A220 I7 D1 T2
GOTO %CONFIG%
:WIN
LH SMARTDRV.EXE
LH MOUSE.COM /Y
WIN
GOTO END
:XMS
LH SMARTDRV.EXE
LH DOSKEY
GOTO END
:END
</syntaxhighlight>

The <code>GOTO %CONFIG%</code> line informs DOS to look up menu entries that were defined within <code>CONFIG.SYS</code>. Then, these profiles are named here and configured with the desired specific drivers and utilities. At the desired end of each specific configuration, a <code>GOTO</code> command redirects DOS to the <code>:END</code> section. Lines after <code>:END</code> will be used by all profiles.