DELOLDOS Command and OLD_DOS Directory Creation Limit (70753)

The information in this article applies to:
    Microsoft MS-DOS operating system 5.0
    Microsoft MS-DOS operating system 5.0a
    Microsoft MS-DOS operating system 6.0
    Microsoft MS-DOS operating system 6.2
    Microsoft MS-DOS operating system 6.21
    Microsoft MS-DOS operating system 6.22

This article was previously published under Q70753


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>:

OLD_DOS.1 ... OLD_DOS.99

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.


If the current DOS directory in use is deleted prior to installation or not detected when installing, an OLD_DOS.x directory is still created when installing; however, it contains only the README.NOW file. Also, any non- DOS files put into the DOS directory aren't saved in the OLD_DOS.x during installation. Those files are put into the new installed DOS directory instead.

Modification Type: Major Last Reviewed: 5/12/2003
Keywords: KB70753