DOS under Win 95
Tue, 4 Jun 1996 10:43:09 -0400 (EDT)
I have seen enough queries over time that I feel this information on DOS and
Win95 might be useful to CT users and the contest community as a whole. If
you have any other questions, please contact me.
Copyright (c) 1996, Robert L. Hummel
In general, Windows 3.x respected the sovereignty of your computer system.
Windows assumed, for example, that you would install DOS, optimize your
memory configuration, and generally perform all the required low-level work.
But doing so properly often resulted in confusion and frustration for new users.
Windows 95 is markedly different. It takes over your system completely,
installing not only itself, but a new version of MS-DOS as well. After
installation, it determines the configuration it needs and stores a record
of those options in a text configuration file named MSDOS.SYS.
In MS-DOS 6.22 and earlier versions of DOS, MSDOS.SYS was one of the two
binary files that made up the DOS system. (The other was called IO.SYS.)
Under MS-DOS 7, however, IO.SYS and MSDOS.SYS have been combined into a
single file called IO.SYS. MSDOS.SYS is now an ordinary ASCII text file. And
by changing the settings in that file, you can wrest back control of your
system from Windows 95.
Prepping for Surgery
Before you can reconfigure your Windows 95 system, you'll need access to
your MSDOS.SYS file. From within Windows 95, click Start, point to Programs,
and then click MS-DOS Prompt. When the DOS prompt appears, type the
ATTRIB -R -S -H MSDOS.SYS
Alternately, you can click the Start button, point to Find, and then click
Files or Folders. In the Named box, type MSDOS.SYS and press Enter. Use your
right mouse button to click the MSDOS.SYS file, and then select Properties.
Click the Hidden and Read Only attributes so their checkboxes are clear.
Click OK. Finally, double-click the MSDOS.SYS file in the results window to
start the editor. (If an editor isn't associated with the file, simply
Regardless of how you get to it, you'll see a file divided into sections by
bracketed titles, much the same way as the WIN.INI and SYSTEM.INI files were
under Windows 3.x.
The [Paths] section is straightforward, containing information about where
Windows 95 can find its files. The selection UninstallDir appears only if
you chose the option to uninstall Windows 95 during installation. The
comment at the end portion of the file is self-explanatory. Don't change the
entries in either of those sections.
The file section that we're interested in begins under the [Options]
heading. In Figure A, this section is empty. Your system may already contain
a few options that relate to networking or double buffering for SCSI hard
drives -- we won't change those. Table A (at the end of the article) lists
and defines the ten options that you can change to control your system.
Before you make any changes to your MSDOS.SYS, back it up. Either copy the
file to another directory or a floppy disk or print out a copy. That way, if
you confuse things too badly, you can always restore your old configuration.
By picking and choosing your MSDOS.SYS options, you can program Windows 95
to suit your particular needs. But there's one configuration that's very
popular: making Windows 95 behave like your old DOS/Windows 3.x system. In
other words, when you turn on your PC, you'll boot to the DOS prompt. Then,
when you need it, you can start Windows with the WIN command. And finally,
when you exit Windows you'll return to DOS, just as you always have.
Doing so requires only a few changes to the [Options] section of your
MSDOS.SYS file. Any options that appear in your MSDOS.SYS file that aren't
specifically listed here should be left exactly as they are. The section
should contain the following commands:
I'm one of those folks that are really bothered by the logo splash screen
that displays when Windows starts up -- its like an unwanted commercial. On
a practical note, the graphic covers up what's going on behind the scenes --
things you may want to watch. Because you're booting into DOS, save a few
nanoseconds by setting Logo=0.
The BootWin=1 option says that you want to boot into the MS-DOS 7 system --
not your previous version of DOS. Setting BootGUI=0 is the next key
component of this new configuration. It tells your system to stop loading
programs when it reaches the DOS command prompt. In other words, it won't
automatically type the WIN command.
To provide the most flexibility, enable the BootKeys and BootMulti options
by setting them to 1. This lets you control the system's boot using the F4,
F5, SHIFT+F5, F6, F8, or SHIFT+F8 keys. The BootMenu=0 option suppresses
display of the boot menu unless you specifically activate it by pressing F8.
By default, Windows writes a log to disk listing the programs and
components it loads. If the system is having trouble with new device drivers
or hardware, this can be useful information. But if the system is running
fine, writing the log just wastes time. To eliminate this unnecessary disk
activity during the boot sequence, disable the log by setting DisableLog=1.
Finally, save your changes and exit the editor. From within Windows 95,
click Start and select Shut Down. Select "Restart the computer" and click
OK. When your PC restarts, you'll be greeted by the MS-DOS 7 prompt! To
verify this, execute the VER command. You should see a response similar to
Window 95. [Version 4.00]
The final step is to create a batch file that will restore your system when
you exit Windows. By default, Windows leaves your system in an unusable
graphics mode. Fixing this requires only that you create a simple batch program.
First, go to your Windows directory; On most systems, this will be
C:\WINDOWS. Next, create a batch file named WIN95.BAT that contains the
following two commands:
Now, when you want to start Windows, use the command WIN95. And when you
exit Windows by choosing Shutdown from the Start menu, you'll be returned to
the familiar DOS prompt.
Table A: These MSDOS.SYS options let you tailor how your Windows 95 system
boots and operates.
= 1 Starts the MS-DOS 7/Windows 95 system.
= 0 Starts the version of DOS that was installed on your system before you
installed Windows 95. The MSDOS.SYS file is renamed to MSDOS.W40 the next
time you boot your system after setting this option and the original DOS
system files are restored.
Default = 1
= 1 Boots directly into the Windows 95 graphical user interface (GUI).
= 0 Boots to the MS-DOS 7.0 prompt. From the prompt, Windows 95 can then be
started with the WIN command.
Default = 1
= 1 Displays the animated Windows 95 logo during startup.
= 0 Disables the Windows 95 logo. You may also disable the logo manually
during boot by hitting the ESC key.
Default = 1
Specifies that Windows should wait n seconds after displaying the "Starting
Windows" message before booting the operating system. During this time, if
BootKeys=1, you can press F8 to activate the boot menu.
Default = 2
= 1 Enables the special boot keys F5, F6, and F8 while the "Starting
Windows" message is displayed during startup.
F4 Boots directly into your previous version of DOS. Enabled only if the
BootMulti option is set.
F5 Bypasses your CONFIG.SYS and AUTOEXEC.BAT files, then boots Windows as
directed by the other options in your MSDOS.SYS file.
SHIFT+F5 Bypasses your CONFIG.SYS and AUTOEXEC.BAT files, then boots the
MS-DOS 7 command prompt regardless of the other options in your MSDOS.SYS file.
F6 Bypasses your CONFIG.SYS and AUTOEXEC.BAT files, then loads Windows,
regardless of the other options in your MSDOS.SYS file.
F8 Activates the boot menu screen.
SHIFT+F8 Processes your CONFIG.SYS and AUTOEXEC.BAT files one line at a
time, asking for confirmation before executing each line.
= 0 Disables the boot keys.
Default = 1
= 1 Enables the F4 key during the "Starting Windows" message to boot
directly into your previous version of DOS. BootMulti works only if BootKeys=1.
= 0 Disables the F4 key. If BootMulti=1, then you can choose option 7 from
the boot menu to select your previous version of DOS.
Default = 0
= 0 The boot menu appears only if F8 pressed when the "Starting Windows"
message is displayed during system startup.
= 1 The boot menu appears automatically during system startup.
Default = 0
Specifies that Windows should wait n seconds after displaying the boot menu
before selecting the option specified by BootMenuDefault. Effective only
when the boot menu is displayed automatically by setting BootMenu=1.
Default = 30
Specifies that Windows should boot option n by default after waiting
BootMenuDelay seconds when BootMenu=1. The default option can be overridden
by manually selecting another option.
Default = 1
= 0 A record of all files processed and loaded during boot is written to
the C:\BOOTLOG.TXT file.
= 1 The C:\BOOTLOG.TXT file is not written.
Default = 0
Rob Hummel (WS1A) <firstname.lastname@example.org>
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