Reregister VSS components to resolve NetWorker backup failures

Sometimes re-registering VSS core components can fix errors and allow NetWorker backups to continue successfully.

On the failing client, use the following commands to attempt to resolve VSS related errors:

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 /s /i swprv.dll
regsvr32 /s /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

vssvc /register

net start swprv
net start vss

vssadmin list writers

Check the vssadmin output that all your writers are displayed without errors. If errors are still shown, then a reboot of the server will be required.

After the reboot, open a command prompt and rerun the vssadmin command

If the output was clean, then attempt another backup of the failed client;