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System State backups fail with the error "application writer's data is not available"

The following event is logged in the Windows Application Event Logs

Log Name:      Application
Source:        VSS
Date:          5/9/2014 3:13:51 AM
Event ID:      8194
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      CARB-ILLYA-W2012
Volume Shadow Copy Service error: Unexpected error querying for the
IVssWriterCallback interface.  hr = 0x80070005, Access is denied.
. This is often caused by incorrect security settings in either the writer or
requestor process. 

What's going on?

This behavior is caused by incorrect or missing COM access permissions. The correct permissions must be set to prevent the error. 


  1. Launch Component Services from Administrative Tools in the Control Panel. 
    1. This is most easily done by typing dcomcnfg into the Start Menu.
  2. In the left portion of the window, expand the Component Services section and then expand the Computers section.
  3. Right-click on My Computer (listed in the Computers section) and select Properties from the pop-up menu.
  4. Click the COM Security tab. The My Computer Properties dialog will appear.
  5. Click the Edit Default... button in the Access Permissions section. The Access Permission dialog will appear.
  6. Under the Group or user names box, click the Add... button.
  7. Type Network Service into the box and click OK.
  8. Click OK on both the Access Permission and My Computer Properties dialogs to close them.
  9. Restart the computer.