The autoexec.bat and the config.sys were files created for MS-DOS and Windows 3.x as an easy solution of
loading the files required for various devices as well as the operating system to properly
run. These files are required for later revisions of MS-DOS and Windows 3.x to load.
Because Microsoft is trying to steer away from MS-DOS, these files are not
required for Windows 95, Windows 98, Windows NT, Windows
ME, Windows 2000,
Windows XP, or later operating systems.
However, in some cases it may still be necessary for users to
edit or configure these files.
How to edit the files
The auotexec.bat and the config.sys are most commonly edited by
the MS-DOS command file Edit. To edit these files, type
edit
c:\autoexec.bat to edit the autoexec.bat file, or edit c:\config.sys
to edit the config.sys file. If the mouse drivers are not loaded properly you will not have
the capability of navigating the mouse.
If you have Windows 95,
Windows 98, or later versions of Windows it is recommended that you use the
sysedit command; to run
this program, click Start / Run and type sysedit.
Remarking information
Remarking lines within the autoexec.bat or the
config.sys allows you to temporarily or permanently prevent a line from loading each time
you boot the computer. This is done by placing "REM "
in front of the line you wish to skip.
If you are encountering issues with a line in the autoexec.bat it is
highly recommended that you remark the line instead of removing it. This will prevent
issues from arising if the line needs to be placed back into the
autoexec.bat.
Getting additional memory
The
below commands will help allow your computer to load
programs into memory more efficiently allowing you to have more memory for MS-DOS programs
/ games.
Ensure you have the
below three lines at the beginning
of your config.sys file.
By placing the DOS=HIGH,UMB on the second line, this can, in some cases, save
memory because it is loading DOS into upper memory before loading the memory manager.
Additionally, the first and third lines cannot be loaded into high memory because these
lines are the memory managers.
Load all your devices in your config.sys and autoexec.bat into high
memory.
Below is an example of what an autoexec may look like:
@echo off
SET SOUND=C:\PROGRA~1\CREATIVE\CTSND
SET BLASTER=A220 I5 D1 H5 P330 E620 T6
SET PATH=C:\Windows;C:\
LH C:\Windows\COMMAND\MSCDEX.EXE /D:123
SET PATH=C:\Windows;C:\
LH C:\Windows\COMMAND\MSCDEX.EXE /D:123
Command
Explanation
@echo off
Tells DOS to just read the lines but don't echo
them back to the screen.
SET SOUND=C:\PROGRA~1\CREATIVE\CTSND
This
example is for the particular sound card
that we have in one of the machines that we have. The set sound is telling the computer to
send all sound events that the computer may run to that directory.
SET BLASTER=A220 I5 D1 H5 P330 E620 T6
Tells the computer to set the
sound blaster settings. This is a good line for game
players; if you have this line in your autoexec.bat you will know all settings
players; if you have this line in your autoexec.bat you will know all settings for your
sound card. A220 = port address "220", I5 = IRQ 5, D1 = DMA 1 usually being the
settings you will need for any game out on the market.
SET
PATH=C:\Windows;C:\
Sets the computer to look in the
C:\windows directory or the root if a command used at the prompt
is not found.
LH C:\Windows\COMMAND\MSCDEX.EXE /D:123
Line used for the CD-ROM. If you
have Windows 95+, the MSCDEX will always be in the
C:\Windows\COMMAND. In Windows 3.x or DOS, this will usually be
either in C:\DOS or C:\Windows
directory. The /D:123 is the name of the driver name that loads
in upper memory; this can be anything, usually /D:MSCD0001.
However, this is not an actual driver, this is just the name for
the driver. Ensure if you change this line that you change it in
the config.sys on your CD-ROM line. If the two are not the same,
your CD-ROM drive will not load.
LH C:\MOUSE\MOUSE.EXE
Loads the mouse
driver into memory. However, not all mice use the same drivers.
Although the mouse may use mouse.exe it could also be "mouse.com" or
"mouse.sys", which is loaded in the config.sys.
C:\DOS\SMARTDRV.EXE
/X
Loads
the smartdrive disk cache utility into memory. See our smartdrv
command page for additional information about this
utility.
DOSKEY
Simple dos
command to load DOSKEY into memory so when
in DOS you can use it without having to load it.
CLS
MS-DOS
command to clear screen.
WIN
Used for
users using Windows 3.x, this line will load Windows automatically
when booting the computer.
Config.sys layout
Below is an example of what the config.sys may look like:
The
Himem.sys line is a very important line; this
line will allow you to load drivers into high memory. If this line is not present, Windows
3.x will not load.
DOS=HIGH,UMB
This line will load DOS into
high memory in an upper memory
block. Note
the location usually best placed after the HIMEM.SYS.
DEVICE=C:\Windows\EMM386.EXE NOEMS
The EMM386
line loads the extended memory manager,
however note that some MS-DOS games have problems with extended memory and will not run without
the NOEMS statement.
FILES=30
The files
line allow Windows to load 30 files at the same time. Usually,
however, going higher may decrease the computer's performance; 30 is found to work the best.
Also ensure that this line is all as one line and that there is not a space between and
after the =.
STACKS=0,0
The stacks
line was first used in MS-DOS 3.2 and was used to swap the stack
whenever an asynchronous hardware interrupt occurred. Later in
MS-DOS 3.3 the line STACKS=0,0 was added into the config.sys. In
special circumstances, this line was changed to STACKS=9,128.
The STACKS statement has a range of
8-64, 32-512. If a higher value is entered you will receive a FATAL
: Internal Stack Failure, System Halted error message.
BUFFERS=20
Buffers
line is to load buffers into memory allowing Windows to load
memory.
DEVICEHIGH=C:\Windows\COMMAND\ANSI.SYS
The
ansi.sys line is a driver for DOS to allow you
to have different colors / sizes and special characters at the DOS prompt.
DEVICEHIGH=C:\MTMCDAI.SYS
/D:123
This line
is the name of the CD-ROM driver on the
particular system we are working on. The /D:123 represents the name of the driver, which in
this case is named 123, however, can be named anything, usually MSCD0001. Note, however, that
/D:123 must be exactly the same in config.sys and autoexec.bat; if they are different, the
CD-ROM will not work in DOS.
LASTDRIVE=
Allows you to specify the last drive installed
on the computer. It is not recommended this line be used unless you are using Windows 3.11
or below. This line can cause issues with Windows 95 & 98 and will generally be
remarked by Windows automatically.
FCBS=
Line used to specify the
number of file-control blocks for file sharing. This line should
only be used when programs require it, and today, is generally not
used or required. FCBS can utilize between 1 and 255.
FORUM
CH000007