Unable to open the item c:\documents and settings\all users\application data\microsoft\network\downloader\qmgr0.dat - skipped.

It happens on all servers being backed up. I believe the files (qmgr0.dat & qmgr1.dat)are created by the systems. What are they and why they are unable to open?

Contributed By: Anna Hester [MSFT]
The qmgr0.dat and qmgr1.dat are files that are created/used by BITS (Background Intelligent Transfer service), and they are constantly in use by the BITS service.  One way of avoiding warnings from backup utilities is to add these files to the "FilesNotToBackup" list (stored in the registry).

To add the BITS qmgr*.dat files to the list, you could do the following:

1) Open the Registry key:
HKLM\SYSTEM\CurrentControlSet\Control\BackupRestore\FilesNotToBackup

2) Create a multi-string value with the value name:
BITS

3) Add the following string to it:
%ALLUSERSPROFILE%\Application Data\Microsoft\Network\Downloader\*

The BITS 1.5 redistributable packages will add this key as part of its setup routine, so another way of solving the problem is to upgrade the BITS version in your system to 1.5.

http://www.microsoft.com/downloads/details.aspx?familyid=8C6EF6C8-2ABF-43C7-AB51-E0C53303086D&displaylang=en

Note that if your system is not an English version of Windows, the "Application Data" part of the path will need to have a translated form.  Unfortunately, BITS 1.5 setup will not automatically detect this situation, so the correction will be needed in both methods.

A second note is that although Microsoft recommends that backup utilities utilize the "FilesNotToBackup" key to obtain a list of files that should be excluded from backup, it is not guaranteed that all backup utilities will in fact take the list into consideration.

Most of the Backup utilities I know will use the FilesNotToBackup list, but I don't know if that's true for Backexec 9.0.