Because this query was originally posted in a Windows XP discussion group, I
forgot to mention that the OS is Win XP SP2 and the backup application is
Microsoft's included Backup Utility.

Per Microsoft Help: When the Backup Utility is configured in "Normal" mode
it turns off the archive flag as you suggest. When the Backup Utility is
configured in "Differential" mode, it only backs up files that have the flag
turned on, and leaves the flag on. So, "Differential" mode should be
cumulative. That is, the backup always contains all files modified since the
last Normal backup.

The first time that a Differential Backup runs after a previous Normal
Backup, it still doesn't backup any of the .dbx files that were modified
after the Normal Backup. This suggests that .dbx files do not have archive
flags (or something is unreliable about them as you state).

Microsoft's Backup Utility doesn't appear to provide any other mechanisms
(like date modified) for determining if a file is backed up (or not). The
only choices a Normal (backs up all files and turns off the archive flag
if on); Differential (only backs up files that have the archive flag on and
leaves the flag on); Incremental (only backs up files that have the flag on
and then turns the flag off).

My recovery policy is to rebuild systems from scratch after a crash (or some
other major system failure). So, I run a Normal Backup of non-replaceable
files once per week and a Differential Backup at Log-On. If .dbx files are
"different", the simple solution seems to be to run an additional Normal
Backup of key .dbx files at Log-On (and suffer the additional time required).




"Michael Santovec" wrote:

Differential backups count on the Archive flag being set for the file.
Normally backup programs turn off the Archive flag. And many
applications that modify a file turn it back on.

Unfortunately, this is not reliable for DBX files.

If the backup has to option to backup based on date modified, you can
use that for DBX files.

--

Mike - http://pages.prodigy.net/michael_santovec/techhelp.htm


"natparke" wrote in message
...
Normal Backup correctly backs up all Outlook Express .dbx files when
the
Outlook Express box is checked (which causes all .dbx files to also be
checked).

Subsequently, Differential Backup (with the Outlook Express box
checked)
does NOT back up any .dbx files after Outlook Express has modified
mail
folders (i.e. the .dbx files).

Differential Backup depends on a file (or folder) being marked by a
flag if
any change has occurred since Normal Backup. Is there something
different
about Outlook Express files that defeat Differential Backup? Outlook
Express
files are not on the excluded files list. Does anyone have a handle
on this
problem? Thanks.