Okay, the SYSTEM permissions don't work for everyone:
http://groups.google.com/group/[email protected]&lr=&hl=en
From MS Knowledge Database:
CAUSE
The DSBackupOpenFile function (one of the Active Directory backup functions)
returns error code 0XC8000408 (JET_errFileAccessDenied) if it encounters a
busy file. Later calls to DSBackupOpenFile return error code 0xC8000208
(JET_errNoBackup), and you must start the backup process again from the
beginning. The most common cause of this problem is an antivirus program
that holds a file open. After you apply the hotfix that is described in this
article, DSBackupOpenFile retries the open action for a maximum of 10
seconds if the function encounters an "access denied" error. If you still
experience the problem after you install the hotfix, contact Microsoft for
more help.
FIX
1. Turn off antivirus, perform update, restart antivirus.
http://groups.google.com/group/[email protected]&lr=&hl=en
2. Download the hotfix: (It's designed for Win2000 and probably won't load
on your machine.)
http://support.microsoft.com/kb/328423