The description below is from the book DOS the
Easy Way by Everett Murdock Ph.D.
for information about downloading the book.
Type: Internal (6.0 and later)
Purpose: Used in the CONFIG.SYS file to set the startup
that will be used by DOS if no key is pressed within the specified
You can only use one MENUDEFAULT= line within a menu block in your
file. The default menu option that you specify with the MENUDEFAULT
only be executed if you do not select another option within the specified
timeout period. You can also stop the timeout count by pressing any key
keyboard during the timeout period. Then you can select an alternative
by using the arrow keys to move the highlight from one option to the
next, or by
entering the line number of the option you want to execute.
For more information about the MENUDEFAULT command, see Chapter 6, Tips for Advanced Users, in the downloadable book DOS the Easy Way.
blockname - Specifies the menu line that DOS will highlight when the
menu is displayed.
timeout - Specifies the number of seconds (0 to 90) that DOS will
wait before starting the system using the default menu option, if no other
option is selected. If 0 is used, the specified option will immediately be
If you want to create a menu in your CONFIG.SYS file that provides a
configuration options upon system startup, any one of the menuitems could
as the default menu option that will be activated if no option is
following example designates the menu option named NORMAL as the default
DOS will automatically select the NORMAL option after 30 seconds.