Backup failure, VSS WMI Writer unregistered

Written By Tami Sutcliffe (Super Administrator)

Updated at March 31st, 2021


Re-register WMI Writer in VSS. 

Applies To                                                                           



Windows Server

Symptoms / Description

Backup jobs fail due to the VSS WMI Writer being in a failed state.  Run "vssadmin info" at the command prompt on the client and look for the following State and Last Error on the WMI Writer.  The VSS WMI Writer may have become unregistered.


Writer name: 'WMI Writer'

State: [9] Failed
Last error: Retryable error



To register the VSS WMI Writer:

  1. Open an commandline console
  2. cd %windir%\system32\wbem
  3. for /f %s in ('dir /b *.dll') do regsvr32 /s %s
  4. wmiprvse /regserver
  5. winmgmt /regserver
  6. net stop replibit
  7. net start replibit
  8. Check the backups