The description below is from the book DOS the
Easy Way by Everett Murdock Ph.D.
for information about downloading the book.
Type: External (5.0 and later)
Purpose: Deletes all files from previous versions of DOS after a
During an upgrade installation of DOS 5.0 or 6.0, your previous version
is stored in a directory named OLD_DOS.1 and on uninstall disks created
DOS Setup program. After you have finished installing and testing the
version of DOS, you can delete your old version of DOS by using the
command. Once you have used the DELOLDOS command, you will not be able
restore your previous version of DOS from the Uninstall disks so be sure
the new version of DOS works on your computer before using this command.
the DELOLDOS command will delete itself from your disk once it has
deleting your old version of DOS.
/B - Specifies a black-and-white screen mode. Used with LCD displays
using a monochrome monitor attached to a CGA adapter.