After I encountered this error, I checked the backup log and I found that NTBackup had been configured to try to back up the Exchange data on our servers. See “Data to Exclude from Windows Backup Sets or Full Computer Backup Sets” and “Backing up Exchange 2000/2003 with NTBackup” for the correct procedure on backing up Exchange.
Per Microsoft: “This problem occurs because the Windows Backup program tries to back up the DO_NOT_REMOVE_NtFrs_PreInstall_Directory folder during the System State backup. The DO_NOT_REMOVE_NtFrs_PreInstall_Directory folder should be skipped by the Windows Backup program. However, there are certain circumstances where Windows Backup tries to back up this folder. This error does not jeopardize the integrity of the backup”. See ME820272
to fix this problem.
contains a Volume Shadow Copy Service (VSS) update package available for Windows Server 2003.
This behavior can occur because the Volume Shadow Copy service places Exchange Server 2003 in a "backup in progress" state, causing the Exchange Server 2003 online backup streaming API to fail to bind to the databases. See "JSI Tip 9366" for information on fixing this problem.
I was getting this EventID 8019 and 8001 in my event log. I found that KB article ME817688
discuses my issue. I have installed the fix and the problem has not reappeared since.