Customer queried part of our backup routine asking about qmgr0.dat as ntbackup is unable to back the files up. Apparently qmgr*.dat files are part of BITS and therefore always in use. More importantly, the faq on mgr0.dat says that there is a registry key that you can use to tell ntbackup (and other backup software?) not to backup these files. This is a great answer to my problem of how to filter out valid skipped files not backed up when you backup c:\
Update You need to use regedt32 to create the registry entries and not regedit