MS-DOS Backup Err Msg: Unable to Open Component File (91664)

The information in this article applies to:
    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 Q91664


If you back up to a network drive, and someone moves your files, you cannot restore them until they are moved back. When you try to restore your files, you receive the following error message:

Unable to open component file


If you back up to a fixed (not floppy) drive, Microsoft Backup creates a .001 file in a .FUL directory. For example, if you back up to F:\TEMP on your fixed drive or a network drive, Backup creates


where xxxxxxxx are numbers and letters generated from the date. Moving the .001 file causes the restore option in Backup to fail and generates the error message.


To work around this problem, re-create your original directory structure and move the .001 file back to its original location. If you cannot remember the original directory structure, attempt to restore your files again. The error message displayed by Backup tells you the directory and filename for which it is looking.

How the Backup Filename in Generated

The backup file for DEFAULT\CCYMMDDA.FUL is calculated as follows:

default = name of backup set
y = last number of year
mm = month of backup
dd = day of backup
a = A - Z, depending on the number backups that day

Modification Type: Major Last Reviewed: 11/26/1999
Keywords: KB91664