Disk Operating System (DOS)

Starting and customizing the MS-DOS Mode in MS-Windows 98 through MS-Windows XP.

MS-DOS Mode in Win98-WinXP

Starting the MS-DOS Mode in Windows

MS-DOS Mode is not like the DOS session which runs inside of Window's protected-mode GUI, it is DOS in Real Mode. It is does not support for long file names, multitasking, or protected mode drivers.

Starting MS-DOS Mode

Method Notes
Boot directly to MS-DOS mode by editing MSDOS.SYS's BootGUI line to BootGUI=0 DOS programs get most resources
Type WIN or EXIT to go to GUI
Select MS-DOS mode from Startup Menu (F8) DOS programs get most resources
Type WIN or EXIT to go to GUI
Restart in DOS mode from the Start menu Leaves a stub of Windows in memory
Inherits DOS environment & DOSKEY TSR
Type WIN or EXIT to go to GUI (this causes machine to reboot)
Exit to DOS PIF Reboots machine Inherits AUTOEXEC DOS environment but not TSR's by default (can be customized in Advanced Tab>MS-DOS Mode>Specify a new configuration

Since there are no protected-mode device drivers in MS-DOS mode, you must load real-mode drivers for any devices that you want to use, including CD-ROM and mouse.

If you are starting the MS-DOS Mode via an exit to DOS PIF, real-mode drivers must be loaded via the customized AUTOEXEC and CONFIG.SYS settings specified in the Advanced tab of the PIF.

(If you are booting directly to DOS drivers are loaded from either CONFIG.SYS or AUTOEXEC.BAT).

Customizing MS-DOS Mode

In the Advanced Tab of DOS PIF properties, place a check in the MS-DOS Mode check box. This makes available the following selections:

Setting Notes
Warn Before Entering check box Determines whether or not you receive a warning before Windows boots to the DOS mode.
Use Current Settings Takes settings from existing AUTOEXEC, CONFIG.SYS, and IO.SYS
Specify a new Configuration Based on Current Settings, but can be modified by adding or removing settings from AUTOEXEC and CONFIG.

When MS-DOS Mode is run, Windows renames the existing CONFIG.SYS to CONFIG.WOS and AUTOEXEC.BAT to AUTOEXEC.WOS.


Bruce Miller, 2002, 2014