Using BACKUP/F After Installing the MS-DOS 5 Upgrade (75837)

The information in this article applies to:
    Microsoft MS-DOS operating system 5.0

This article was previously published under Q75837


After installing the Microsoft MS-DOS 5 Upgrade, the BACKUP command can return the message "Incorrect DOS version" if you try to format a disk during the backup procedure using the /f[:size] parameter.


BACKUP can appear to work correctly for the first few disks, but when the BACKUP command tries to back up the OLD_DOS.X directory it attempts to use the older version of FORMAT.COM.

To correct the problem, remove or rename all old FORMAT.COM files from your computer OR delete the OLD_DOS.X directory using DELOLDOS.EXE.

To find all occurrences of FORMAT.COM, type the following from the root directory:


More information on the BACKUP command can be found in the "Microsoft MS-DOS User's Guide" on pages 370-373.

Modification Type: Major Last Reviewed: 11/22/1999
Keywords: KB75837