CONFIG.SYS - features, requirements and recommendations

Table of contents:

CONFIG.SYS - features, requirements and recommendations
CONFIG.SYS - features, requirements and recommendations

Previously, the only way to get the user's settings when the computer boots up was with two files stored in the main directory of the boot disk AUTOEXEC. BAT and CONFIG. SYS. These files are still required for the new MS. DOS and Win update, but it is believed that they are no longer needed in newer versions of Windows. This would be the case if Microsoft changed the way DOS was handled, but for now, things remain the same.

So they continue to work with an automatic execution batch file (AUTOEXEC) and a bootstrap configuration file (CONFIG), which are edited by the MS-DOS batch file. To do this, enter edit c:\autoexec.bat or c:\config.sys. into the command line

A bit of theory


Batch files are just lists of commands. Many PC users who have had no problems with downloads do not know them very well and confuse the CONFIG and AUTOEXEC files with each other. CONFIG is much more than just SYS. However, it is the same list of commands in the form of a text file with instructions for the computer. The two files are really similar to each other, they havea lot in common.

When the PC turns on, it checks all drives, peripherals and fills the memory. CONFIG. SYS does most of this work. Some functions can be handled by a batch file. But there are important tasks that only CONFIG can handle. He is always on the "front line" when the computer boots up.

Built-in BIOS routines

After the PC runs its onboard BIOS routines, the code in the BIO looks up CONFIG to see what to do next. This happens a little differently on old and new computers, but the principle is the same. CONFIG. SYS is allowed to complete its task before DOS can load its shell. The DOS part is just tons of disk and screen code, and the other part is the shell. When a user or batch file enters a command, the processor does the work.

CONFIG. SYS can tell the computer when to load memory managers or CD-ROM drivers before DOS has a chance to know what's going on. If the PC tried to load things like this after DOS had finished booting, many of them wouldn't work, and CONFIG. SYS could output a DOS shell and load a replacement:

Embedded BIOS routines
Embedded BIOS routines

Very few people use a shell replacement on their PC, but it can be done very easily by typing the full path right after the shell=.

Reorganizing files

Because CONFIG SYS dos has all launchersfunction, it receives the first signal before DOS starts up. Therefore, it is always better to add commands to CONFIG rather than to a batch file if the user has the ability to do the editing. Many programs that are normally written to a computer in AUTOEXEC can indeed only be placed in CONFIG. For example, you can put a PATH statement in a batch file, which is almost always the default, but the best way to specify PATH is in a configuration file.

File reorganization
File reorganization

On the one hand, the path will be created before the shell starts running, and on the other hand, the PATH statement will take up slightly less memory when placed in the CONFIG SYS command. The same can be said about the SET function. Almost all users who have AUTOEXEC put its instructions in the wrong place. Better move them to CONFIG.

Benefit of optimized startup

One of the advantages of a batch file is that it only works when the shell is in position and can run programs. Few people know that the configuration file can also do this. It won't run Microsoft Word or an Internet browser, but it can do the job with utilities that go into memory and stay there. In fact, any program loaded with CONFIG. SYS will usually remain in memory.

The INSTALL or INSTALLHIGH commands do this. The latter makes better use of memory. Typical programs that can be loaded into a configuration file areinclude FASTOPEN and SHARE, both do not work in Windows 95. But many other small programs will load fine in CONFIG. If the user runs a utility in a batch file using the LOAD or LOADHIGH command to see if it works in CONFIG. SYS, this is a bad experiment. It won't work, it might fail. If an experiment is needed, then they first load and test simple operations, then they do something serious.

To check an INSTALL or INSTALLHIGH command in a configuration file, simply put a question mark before the line containing the command. When the computer boots, the user will be asked if they want to activate the command on this line. If something goes wrong, restart the PC, skip this line when it appears, and then edit the CONFIG SYS file and remove the stub.

Function value table

For those users who work with the CONFIG program, knowledge of function values is very often required. We put them in the table:

Function Meaning
BREAK Installation and cleanup, with extended check CTRL + C
CD and CHDIR Change directory or display current one
CHCP Display valid character sets
CLS Screen refresh
COPY Copy files todesired location
CTTY Computer management by changing the terminal device
DATE Set present date
DEL Delete specified files

Display current folder location list

EXIT Exit COMMAND and return to previous program
LH and LOADHIGH Loading utility to upper memory
LOCK Enabling direct access to the storage for storing and retrieving data from it without the participation of the processor
MD Creating a folder or subfolder
PATH Specification of Windows 95 folders that will be searched by executing documents
PROMPT Change the appearance of the command line
RD and RMDIR Destroying a folder
REN and RENAME Edit file names
SET Display setting environments
TIME Display or set the current time


Display text document
UNLOCK Disabling direct disk access
VER Display OS version number
VERIFY Instructing the OS to ensure that files are written to disk correctly, displaying the status of checks
VOL Display the volume label and serial number for the drive

Check configuration

Because the configurations vary, in practice it is recommended to check which version of DOS is being used. Procedure:

  • Press Windows-R to open the Run menu.
  • Type cmd and press Enter for command prompt.
  • Type cd \ and press Enter.
  • Type edit config.sys in the command window to open the editor for the config file.
  • Enter configuration parameters for Config.
  • Himem is a high memory manager that boots DOS and EMM386. Extended memory support, disabled by noems.
  • Add all devices that need to be loaded into the configuration file using the DEVICEHIGH command.
  • Enter LASTDRIVE=S, where S is the last drive letter to be used for DOS.
  • Add CONFIG SYS file commands to change menu in configuration and load [MENU] MENUITEM STARTUP. This displays a menu on startup with Startup and Network items.
  • Next in the file enter [STARTUP] along with any commands to run underthis element, such as the base configuration in the previous example, which allows you to specify commands for different configurations based on upcoming tasks.
  • Press Alt-F then S to save the file, then select Save.
  • Press Alt-F then X to exit or choose Exit from the menu.

Getting more memory

The following commands help the computer load programs into memory more efficiently, allowing more room for MS-DOS programs and games. First make sure that there are the following three mandatory lines at the beginning of the config.sys file:

Getting more memory
Getting more memory

Putting DOS=HIGH, UMB on the second line will save space by loading DOS into high memory before loading the memory manager. Below is an example of what a batch file might look like:

batch file
batch file

The following commands for the convenience of information perception, we also put in the table:

Team Explanation
@echo off Tells DOS to read lines but not write them back to the screen
SET SOUND=C:\PROGRA~1\CREATIVE\CTSND The sound set tells the computer to send all sound events that the computer can put in this directory

SET BLASTER=A220 I5 D1 H5 P330 E620 T6

Tells the computer to configure settingsSound Blaster, which is a good line for games or other programs that require sound (if there is this line in autoexec.bat and all the settings for the sound card). A220 is port address 220, I5 is IRQ 5 and D1 is DMA 1. These settings are typical for most sound cards.
SET PATH=C:\Windows;C:\ Sets the computer to search C:\Windows or root if the command used at the prompt is not found

Line used for CD-ROM. Windows 95+, MSCDEX will always be in C:\Windows\COMMAND. On Windows 3.x or DOS, this file is located in the C:\DOS or C:\Windows directory. /D:123 is the name of the driver that is loaded into high memory. Usually /D:MSCD0001. You need to keep in mind that this is not a driver, but its name. If you change this line, it also needs to be adjusted in config.sys on the CD-ROM line. If these two values do not match, the CD-ROM drive will not boot.

LH C:\MOUSE\MOUSE. EXE Loads the mouse driver into memory. However, not all mice use the same drivers. This can be mouse.exe or, as well as mouse.sys, which is loaded into config.sys.
C:\DOS\SMARTDRV. EXE /X Loads the smartdrive disk cache utility into memory. More information about this utility can be found on the smartdrv command page.
DOSKEY DOS to boot DOSKEY intomemory
CLS MS-DOS Screen Cleaner
WIN Needed for users running Windows 3.x. This line automatically loads Windows.

Mobile phone configuration

Mobile phone configuration
Mobile phone configuration

For privacy and security reasons, sometimes you need to disable MTP and PTP on your mobile device. For example, when the status bar shows that the smartphone is connected as a camera with PTP. This can happen with any USB hub. The user will not be aware of the failure until they connect to it. This operation is carried out using config. For example, to run Android 5.0.2 on Samsung, do the following:

  • Turn on USB setup.
  • Connect to USB.
  • Root the apparatus and confirm the result.
  • Check in emulator setprop sys usb CONFIG: $ su sh -c 'cat /data/property/persist.sys.usb.config' adb.
  • Disconnect the Rebooted cable.
  • Connect to USB.
  • After that, the device will automatically be connected as a media, the parameters remain by default with the parameters setprop sys usb CONFIG diag adb:$ su sh -c 'cat /data/property/persist.sys.usb.config' mtp.
  • After disabling the USB setup, it will reboot and go through the recovery process mtp, adb.

Disabling unauthorized files on XP

Disabling Unauthorized Files on XP
Disabling Unauthorized Files on XP

Very often duringComputer startup turns on programs in the background, which affects its performance. Viewing the list of programs will help you decide whether to enable or disable these files. The XP Start menu contains the System Configuration Editor, which displays applications. In addition, the System Configuration window registers these applications in the Startup tab.

Edit system configuration CONFIG SYS Windows XP:

  • Enter sysedit.exe into the start menu and then click OK to open the System Configuration Editor windows.
  • Click C:\config to open the window.
  • Press "Start", then "Run".
  • Enter msconfig and then click OK to display the System Configuration window.
  • Go to the Launch tab to view these boot files and edit their work.

Restarting the computer without loading functions

This example is based on a 24 MB RAM home computer with multiple boot configurations and a batch file that only loads the scanner when needed by the user. Thus, the PC leaves space in its RAM. The average user uses this feature to load peripherals only when needed.


  1. Download all software and hardware first.
  2. Then modify the config and autoexec files.

Most installation procedures don't know how to handle multiple configurations. All environment variables will be shown hereconfiguration file. Before starting, perform BACKUP.

Operations table:

[MENU] Start a file with the [MENU] command. Follow it with various menu items
menuitem=Games The menudefault line indicates which menu item to select, time in seconds. If the user did not select it, then the games will start after 10 seconds
menuitem=Network The config file must have a TAG for each menu item the user has set. If it has nothing in config but only in a batch file, it must be configured too.
menuitem=Games & Network Games & Web
menudefault=Games, 10 The [COMMON] tag is optional and can be used for commands to be separated by each configuration. Instead of repeating the same command in each tag, follow all tags with [COMMON] and add common commands
[Games] Put everything here to match the requirements of the game
[Network] Put something here for the web
[Scanner] Put something here for the scanner
[Games &Network]

Put something here for both gaming and web. ATmost of the time, each of the sections above will be repeated.

The following code is written.

Restarting the computer without loading features
Restarting the computer without loading features

Custom upload hosting

To do this, the Autoexec.bat file is corrected, taking into account that NO is returned after SET PATH. The path pointer must be on one line. To find out if the length of a path exceeds the limit, from the DOS command line type: path followed by ENTER, it will return the path operator. This way you can make sure everything is included in the batch file.

Hosting custom downloads
Hosting custom downloads

Before any changes, perform a BACKUP first. rem multiple configuration.

Table of important commands:

rem multiple configuration Start with rem.
PROMPT=$P$G The PROMPT command tells you what to use for the command line. In this case $ P $ G will make the command line a:
Command Path

C: \>

Put here everything that is available for all configurations. Sometimes you can specify some general things, depending on how they need to be loaded

IF %CONFIG%==Games & Network GOTO Games In this case load the Soundblaster material. If the PC is low on memory, it may be necessary to have soundblaster disabled for certain instances and enable it separately


:Games rem here you would load your joysticks, and/or whatever is necessary for your games.

IF %CONFIG%==Games & Network GOTO Network GOTO END

If the config tag selected by the user in the config file is Games & Network, you can report it to GOTO Games. After the games are over, check again and direct him to go online.
:Network rem here load your network commands. I prefer keeping my network commands in a separate.bat file and calling that.bat file from here. GOTO END This will save the user from having to duplicate information in the Games & Network tag. The GOTO%CONFIG% command instructs the.bat file to go to the TAG for the configuration selected by the user from the config.sys file.

:Scanner rem load your scanner stuff here GOTO END


Now you can put your tags. Place a COLON followed by a tag, just like entering a config file.
SET PATH=C:;C:\a\vj\EAB\jdk\bin;C:\a\vj\EAB\bin;C:\a\vj\EAB\odbc32;C:\D2 \BIN;C:\D2\FUNCTION;C:\D2\SNA\SYSTEM;C:\A\J1\BIN;C:\A\ZIP;c: \COREL\OFFICE7\SHARED\TRUEDOC\BIN After completing each tag section, use GOTO END to exit it and jump to the END tag below.

As you can see, two iconic files play the roles of the old MS-DOS world, but they have not lost their relevance today. If the user has software ora hardware device that needs a driver that is not in the IO. SYS file or in the Windows registry will need to use the commands found in the CONFIG and AUTOEXEC files.

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