Microsoft KB Archive/38112

From BetaArchive Wiki
Knowledge Base

Backing up to Floppy Disks in MS-DOS 4.0 and 5.0

Article ID: 38112

Article Last Modified on 10/13/2003


  • Microsoft MS-DOS 4.0 Standard Edition
  • Microsoft MS-DOS 5.0 Standard Edition

This article was previously published under Q38112


When using a floppy-disk drive as the destination drive, MS-DOS versions 4.x and 5.x BACKUP.COM automatically format the destination disk if necessary. To format the disk, BACKUP executes FORMAT.COM.

To find FORMAT.COM, BACKUP first searches the current directory, and then uses the PATH environment variable for search paths if FORMAT.COM is not found in the current directory. When BACKUP finds FORMAT.COM, it checks to see if FORMAT.COM is on the destination disk. If FORMAT.COM is on the BACKUP destination disk, BACKUP continues the search. If FORMAT.COM is not found, or if it is found only on the destination disk, BACKUP gives the following message and terminates:

FORMAT.COM not found


The following are workarounds for this problem:

  • If more than one drive is available, make sure that either the second drive contains FORMAT.COM and is in the PATH, or the second drive is the destination drive.
  • If the system has only one disk drive, the following statement will cause the destination drive to be the same physical drive, but a different logical drive:

    backup a:\<file specification> b: <possible switches>

  • If the destination disk has a different capacity than the destination disk drive (for example, a 360K disk in a 1.2-megabyte disk drive), you need to specify this using the /f: switch with the BACKUP command. For example, suppose drive B is a 1.2-megabyte drive, and the destination disk is a 360K disk. To back up all the files on drive A to drive B, the following command is needed:

    backup a:\*.* b: /f:360k

Additional query words: 4.00 5.00

Keywords: KB38112