SUMMARY
In the Microsoft MS-DOS Upgrade for versions 5.0 and later, DELOLDOS
command deletes all OLD_DOS.x directories residing in the root directory of
the boot drive. Upon deletion of the these directories, DELOLDOS.EXE itself
is also deleted from the directory it resides in.
The MS-DOS Upgrade installation process can create a total of 99 old DOS
directories named OLD_DOS.<x>:
The <x> value is based upon the integer extensions of any previous OLD_DOS
directories residing in the root directory of the boot drive, so that <x>
is the next integer available in order starting at 1. When the installation
process attempts to create the 100th OLD_DOS directory, it instead replaces
the last OLD_DOS directory made, creating a directory with the same name.