Windows Server Volume Shadow Copy not working

Symptom: On Windows Server 2003 (SBS, Standard, etc.), error 0x8004230f (“The shadow copy provider had an unexpected error”) occurs when running NTBackup and/or when the Volume Shadow Copy scheduled task(s) run.

Cause: This error can occur If certain VSS DLLs are not registered properly, or if something
is wrong with the VSS provider.  This issue is often associated with the installation of new hard drives, especially when deploying previously-created hard drive images to them.

Resolution:

1. Apply the latest VSS package (KB940349) on the server from Microsoft here, and reboot the server.
2. Re-register the VSS related DLLs by running the following commands (a batch file would probably be a good idea here):

cd /d %windir%\system32
net stop vss
net stop swprv
regsvr32 /s ole32.dll
regsvr32 /s oleaut32.dll
regsvr32 /s vss_ps.dll
vssvc /register
regsvr32 /i swprv.dll
regsvr32 /i eventcls.dll
regsvr32 /s es.dll
regsvr32 /s stdprov.dll
regsvr32 /s vssui.dll
regsvr32 /s msxml.dll
regsvr32 /s msxml3.dll
regsvr32 /s msxml4.dll

NOTE: The command in the final line may fail– this is normal.

3. Delete the following registry key (after exporting for a backup):

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\STORAGE\Volume]

4. Reboot the system, and the “VOLUME” key will be recreated, hopefully fixing the issue.