Troubleshooting VSS

Article Number: 


This article details how to troubleshoot VSS errors.


Backups may fail if Microsoft’s VSS framework is in a bad state due to clashes between ShadowProtect and other programs trying to use VSS at the same time (See article on "Understanding VSS and ShadowProtect"), or if necessary system services have been mistakenly disabled. To resolve issues caused by a bad state, the system must be cleaned up before backups will function properly. 


If Microsoft's VSS framework and/or some of the VSS writers are in a bad state, you need to clean the system up before your backups will work.

1. Cancel any running backup jobs, ending the ShadowProtect SVC process if necessary.

2. Go to Start | Run and enter "services.msc" - Click OK. Verify each startup type is set correctly:

        1. Navigate to MS Software Shadow Copy Provider. Startup Type should be set to "Manual" if it is not already.
        2. Navigate to Volume Shadow Copy. Startup Type should be set to "Manual"
        3. Navigate to ShadowProtect Service. Startup Type should be set to "Automatic" 
        4. Navigate to StorageCraft Shadow Copy Provider. Startup type should be set to "Automatic"

3. Delete all greyed-out devices (non-present “Storage Volume shadow copies” devices) from previous snapshots:

        1. Run the command prompt as Administrator.
        2. Run “vssadmin delete shadows /all”, and select “yes” to delete all.
        3. Run devmgmt.msc to open the Device Manager with the option to show non present devices.
        4. Select “View | Show hidden devices” from the Device Manager.
        5. Scroll down until you see “Storage volume shadow copies” in the list.
          1. If it is not listed, see the previous step. Under “Storage volume shadow copies” a listing called “Generic volume shadow copies” will be shown. The icon next to them will be greyed-out. 
        6. Remove these items one at a time by right clicking each item and choosing uninstall. Repeat this process until all greyed-out devices are removed.

NOTE: Do not delete any of the Storage Volumes.

4. Verify state of services:

        1. Go to Start | Run, enter “cmd”, and click OK. 
        2. Run the command: “vssadmin list writers”. This will display the state of any VSS-aware applications.
        3. If any of the VSS-aware applications are in an unstable state:
          • Troubleshoot the individual writer and error.
          • For Server 2003 or Earlier only: Manually reset the state of the VSS writers.

5. Reboot the system.

6. After rebooting:

        1. Go to Start | Run, enter “cmd”, and click OK.
        2. At the C:\ prompt type “vssadmin list writers” and verify all services are in a stable state. No existing shadow copies should be shown.


Following the steps listed above should clean the system up enough for you to start using ShadowProtect. Proper VSS interaction is very complex and many backup products leave various components (especially VSS writers) in bad states. This can cause problems for other backup products. If you are using any other backup products, it's very likely that they will corrupt the states of various VSS components.  You must always ensure that ShadowProtect does not run at the same time as other backup software such as Backup Exec, Acronis, etc. 

Additional Information:

Related articles:

Understanding VSS and ShadowProtect - gives more basic information on what VSS is, how it works and which Operating Systems and applications are VSS aware.

Reregistering VSS steps for Server 2003: (Also referenced in the article labled: VSS Backups fail with a VSS error of 0x8000FFFF)

Warning From Microsoft in reference to the information below:

MS VSS Warning

To attempt to reregister/reset VSS follow Microsoft's  support knowledge base article listed at:

Error message when you run the "vssadmin list writers" command on a Windows Server 2003-based computer: "Error: 0x8000FFFF"

Scroll down to the section labled:

"Let me fix it myself"

Follow this section of Microsoft's document.  .


      • On 64bit system's the path to some DLL's will need to be entered differently because they reside in the SysWOW64 section of the WINDOWS directory.  e.g.

Net stop vss
Net stop swprv
regsvr32.exe /i %windir%\system32\eventcls.dll
regsvr32.exe /i %windir%\system32\swprv.dll
regsvr32.exe %windir%\system32\vssui.dll
regsvr32.exe %windir%\SysWOW64\vss_ps.dll
regsvr32.exe %windir%\SysWOW64\msxml.dll
regsvr32.exe %windir%\SysWOW64\msxml2.dll
regsvr32.exe %windir%\SysWOW64\msxml3.dll
regsvr32.exe %windir%\SysWOW64\msxml4.dll
regsvr32.exe %windir%\SysWOW64\ole32.dll
regsvr32.exe %windir%\SysWOW64\oleaut32.dll
regsvr32.exe %windir%\SysWOW64\es.dll
regsvr32.exe %windir%\SysWOW64\comsvcs.dll
vssvc /register

      • You may not have the msxml4.dll installed.  Though they are not required, If you are missing msxml4.dll or msxml4r.dll (they should be in your system32 directory) and want to have them installed, then you can Windows Update and update Explorer. and then rerun the command for these DLLs after they are in your system32 directory.
      • After reboot you should run the following command and check if all the VSS writers states are good/stable:

"C:\> vssadmin list writers"

      • And this command should show no existing shadow copies:

"C:\> vssadmin list shadows"

      • At this point things should be cleaned up enough for you to start using ShadowProtect. Proper VSS interaction is a very complex affair and many backup products (including,Microsoft's own backup softwares) can leave various components, especially VSS writers, in bad states.  This can cause problems for other backup products. So if you are using any other backup products, it's very possible that they may continue to damage the states of various VSS components.
vss_reg.zip1.31 KB

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