I'm running Windows 2008 SP2 32 bit and my backups are failing due to VSS on only 1 server. I am running other Win 2008 servers without a problem. Source VSS Event ID 12292 Volume Shadow Copy Service error: Error creating the Shadow Copy Provider COM class with CLSID {79079d5c-ef20-4952-b9fc-cfd443b38641} [0x80040154]. Operation: Obtain a callable interface for this provider Add a Volume to a Shadow Copy Set Context: Provider ID: {f782463b-33bb-4043-ad8d-60b728d26a6c} Class ID: {79079d5c-ef20-4952-b9fc-cfd443b38641} Snapshot Context: 0 Execution Context: Coordinator -------------------------------------------------------------------------------- Source VSS Event ID 22 Volume Shadow Copy Service error: A critical component required by the Volume Shadow Copy service is not registered. This might happened if an error occurred during Windows setup or during installation of a Shadow Copy provider. The error returned from CoCreateInstance on class with CLSID {79079d5c-ef20-4952-b9fc-cfd443b38641} and Name SW_PROV is [0x80040154]. Operation: Obtain a callable interface for this provider Add a Volume to a Shadow Copy Set Context: Provider ID: {f782463b-33bb-4043-ad8d-60b728d26a6c} Class ID: {79079d5c-ef20-4952-b9fc-cfd443b38641} Snapshot Context: 0 Execution Context: Coordinator ---------------------------------------------------------------------------- Source VSS Event ID 12292 Volume Shadow Copy Service error: Error creating the Shadow Copy Provider COM class with CLSID {79079d5c-ef20-4952-b9fc-cfd443b38641} [0x80040154]. Operation: Obtain a callable interface for this provider List interfaces for all providers supporting this context Check If Volume Is Supported by Provider Add a Volume to a Shadow Copy Set Context: Provider ID: {f782463b-33bb-4043-ad8d-60b728d26a6c} Class ID: {79079d5c-ef20-4952-b9fc-cfd443b38641} Snapshot Context: 0 Snapshot Context: 0 Execution Context: Coordinator Provider ID: {00000000-0000-0000-0000-000000000000} Volume Name: \\?\Volume{2f2b411a-e9cc-11df-ba6d-806e6f6e6963}\ Execution Context: Coordinator ------------------------------------------------------------------------------------------ I was also getting Event ID 8193 so I followed this article: http://social.technet.microsoft.com/Forums/en/winserverfiles/thread/7b52f7c1-a783-409e-9af3-da64567676df I also found these other articles but didn't help: http://support.microsoft.com/kb/2009513 http://support.microsoft.com/kb/940184/en-us here's what I get when I run VSSADMIN LIST WRITERS: C:\Windows\System32>vssadmin list writers vssadmin 1.1 - Volume Shadow Copy Service administrative command-line too (C) Copyright 2001-2005 Microsoft Corp. Writer name: 'SqlServerWriter' Writer Id: {a65faa63-5ea8-4ebc-9dbd-a0c4db26912a} Writer Instance Id: {8ca9e016-5fc6-462a-bf78-0030129a83fd} State: [1] Stable Last error: No error Writer name: 'ASR Writer' Writer Id: {be000cbe-11fe-4426-9c58-531aa6355fc4} Writer Instance Id: {0bd7f974-9a4d-491d-a74e-cab9637bebde} State: [1] Stable Last error: No error Writer name: 'Shadow Copy Optimization Writer' Writer Id: {4dc3bdd4-ab48-4d07-adb0-3bee2926fd7f} Writer Instance Id: {c38326be-436b-43eb-a934-11949e41ab78} State: [1] Stable Last error: No error Writer name: 'Registry Writer' Writer Id: {afbab4a2-367d-4d15-a586-71dbb18f8485} Writer Instance Id: {eeee0468-b271-4119-8267-be0be9b7c61a} State: [1] Stable Last error: No error Writer name: 'IIS Metabase Writer' Writer Id: {59b1f0cf-90ef-465f-9609-6ca8b2938366} Writer Instance Id: {0d1d1610-6583-431b-980d-0adbf05dc04a} State: [1] Stable Last error: No error Writer name: 'BITS Writer' Writer Id: {4969d978-be47-48b0-b100-f328f07ac1e0} Writer Instance Id: {0f00beeb-47df-4a19-bd1c-1cb4a6631a30} State: [1] Stable Last error: No error Writer name: 'DFS Replication service writer' Writer Id: {2707761b-2324-473d-88eb-eb007a359533} Writer Instance Id: {dae9e878-bc56-4b52-808f-627e59d63b7d} State: [1] Stable Last error: No error Writer name: 'COM+ REGDB Writer' Writer Id: {542da469-d3e1-473c-9f4f-7847f01fc64f} Writer Instance Id: {60181fe2-c436-40ff-8ae2-f9b695170206} State: [1] Stable Last error: No error

Dear friend, You have a missing writer. It's name is 'System Writer' Read the following link to fix this issue: http://social.technet.microsoft.com/Forums/en-US/windowsserver2008r2virtualization/thread/75db9f31-9d2f-46d0-a35a-b7edcbaa51c8 I had the same problem and managed to fix it with the above link.

Actually I do have the System Writer. I just had to reboot after re-registering the DLLs. I also tried uninstalling/re-installing my backup agent (Symantec Backup Exec 2010) but that didn't help either. Here's what I get now when I run the VSSADMIN LIST WRITERS command: P:\>vssadmin list writers vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool (C) Copyright 2001-2005 Microsoft Corp. Writer name: 'System Writer' Writer Id: {e8132975-6f93-4464-a53e-1050253ae220} Writer Instance Id: {d8befe28-224c-43fb-a841-2153f7a7d6b4} State: [1] Stable Last error: No error Writer name: 'FSRM Writer' Writer Id: {12ce4370-5bb7-4c58-a76a-e5d5097e3674} Writer Instance Id: {ba420726-9740-4767-a912-e5347545068f} State: [1] Stable Last error: No error Writer name: 'SqlServerWriter' Writer Id: {a65faa63-5ea8-4ebc-9dbd-a0c4db26912a} Writer Instance Id: {86ed426c-20b6-4abf-a8a3-7fab76b744e8} State: [1] Stable Last error: No error Writer name: 'Registry Writer' Writer Id: {afbab4a2-367d-4d15-a586-71dbb18f8485} Writer Instance Id: {f173587d-f577-499a-9ee2-37cccfaff6d7} State: [1] Stable Last error: No error Writer name: 'IIS Config Writer' Writer Id: {2a40fd15-dfca-4aa8-a654-1f8c654603f6} Writer Instance Id: {691a96cf-22f9-4dc9-a79b-99febbb2c942} State: [1] Stable Last error: No error Writer name: 'ASR Writer' Writer Id: {be000cbe-11fe-4426-9c58-531aa6355fc4} Writer Instance Id: {25051184-4dd4-42e6-895f-c2757bff750c} State: [1] Stable Last error: No error Writer name: 'Shadow Copy Optimization Writer' Writer Id: {4dc3bdd4-ab48-4d07-adb0-3bee2926fd7f} Writer Instance Id: {4f635521-7259-4f69-8546-5d089df99ecb} State: [1] Stable Last error: No error Writer name: 'COM+ REGDB Writer' Writer Id: {542da469-d3e1-473c-9f4f-7847f01fc64f} Writer Instance Id: {f8ba349a-5764-4ec4-984d-eeb1a1e5e232} State: [1] Stable Last error: No error Writer name: 'IIS Metabase Writer' Writer Id: {59b1f0cf-90ef-465f-9609-6ca8b2938366} Writer Instance Id: {4f777830-cf27-434b-88f6-407f61ef6710} State: [1] Stable Last error: No error Writer name: 'DFS Replication service writer' Writer Id: {2707761b-2324-473d-88eb-eb007a359533} Writer Instance Id: {3fc45d4c-509d-472f-a920-b6b0168cc073} State: [1] Stable Last error: No error Writer name: 'WMI Writer' Writer Id: {a6ad56c2-b509-4e6c-bb19-49d8f43532f0} Writer Instance Id: {8b9ee638-32cc-4f45-8f8b-d2f34edde68d} State: [1] Stable Last error: No error P:\>

I figured out what it was. It was a 3rd party VSS writer (Acronis software). I removed the writer from the registry and it's working now. HKEY LOCAL MACHINE\SYSTEM\CURRENT CONTROL SET\SERVICES\VSS\PROVIDERS

Thanks for your sharing. It worked for me.