I have been backing up to a locally mounted Network Attached Storage (NAS)
hard drive on a daily schedule, five different files, one for each weekday.
The files on the hard drive are updated each day, as expected.

When I tried to restore, I got the message, "the backup file contains
unrecognized data and cannot be used". I got the same message for each. I
looked at the "catalog" for the file, shown in the "Restore & manage media"
tab, and the weekday files were not shown.

Here is the backup command from the Monday schedule item:
C:\WINDOWS\system32\ntbackup.exe backup "@C:\Documents and Settings\David
Luce\Local Settings\Application Data\Microsoft\Windows
NT\NTBackup\data\Monday Night.bks" /n "Monday Incremental.bkf created
2/25/2006 at 11:47 AM" /d "Set created 2/25/2006 at 11:47 AM" /v:yes /r:no
/rs:no /hcff /m incremental /j "Monday Night" /l:s /f "E:\Backup
BeechTree6\Incremental\Monday Incremental.bkf"

Does some wierd service need to run to support the basic XP backup?