Hello everyone, first of all, I've looked at lots of forums and lots of threads on this forum to find an answer that could help me but no luck so here I go. My client has a Dell T310 sever with SBS 2011 Essentials (No sharepoint, No Exchange) as domain controller and file server. Since the installation of a program called Zensoft (which basically is an ERP which uses a MySQL database), the Windows Server Backup doesn't run anymore. In Windows Server backup it sais "A volume Shadow Copy Service operation failed. Detailed error: The volume shadow copy operation failed with error 0x800423F4. View the vent log for more information". So that's what I did. I went to the eventviewer which showed me one VSS warning and one Backup error. VSS Warning A VSS writer has rejected an event with error 0x800423f4, The writer experienced a non-transient error. If the backup process is retried, the error is likely to reoccur. . Changes that the writer made to the writer components while handling the event will not be available to the requester. Check the event log for related events from the application hosting the VSS writer. Operation: PostSnapshot Event Context: Execution Context: Writer Writer Class Id: {b2014c9e-8711-4c5c-a5a9-3cf384484757} Writer Name: NTDS Writer Instance ID: {d093c4e7-e0d1-4a4a-b0d9-62558f3fff67} Command Line: C:\Windows\system32\lsass.exe Process ID: 524 Backup error The backup operation that started at '2012-05-09T12:38:29.928000000Z' has failed because the Volume Shadow Copy Service operation to create a shadow copy of the volumes being backed up failed with following error code '2155348129'. Please review the event details for a solution, and then rerun the backup operation once the issue is resolved. There is no solution in the event details... VSSADMIN LIST WRITERS C:\Users\administrator>vssadmin list writers vssadmin 1.1 - Volume Shadow Copy Service administrative comm (C) Copyright 2001-2005 Microsoft Corp. Writer name: 'Task Scheduler Writer' Writer Id: {d61d61c8-d73a-4eee-8cdd-f6f9786b7124} Writer Instance Id: {1bddd48e-5052-49db-9b07-b96f96727e6b} State: [1] Stable Last error: No error Writer name: 'VSS Metadata Store Writer' Writer Id: {75dfb225-e2e4-4d39-9ac9-ffaff65ddf06} Writer Instance Id: {088e7a7d-09a8-4cc6-a609-ad90e75ddc93} State: [1] Stable Last error: No error Writer name: 'Performance Counters Writer' Writer Id: {0bada1de-01a9-4625-8278-69e735f39dd2} Writer Instance Id: {f0086dda-9efc-47c5-8eb6-a944c3d09381} State: [1] Stable Last error: No error Writer name: 'ASR Writer' Writer Id: {be000cbe-11fe-4426-9c58-531aa6355fc4} Writer Instance Id: {c3fdd3ff-b919-4cfa-8c4e-5436fcf62d4d} State: [1] Stable Last error: No error Writer name: 'System Writer' Writer Id: {e8132975-6f93-4464-a53e-1050253ae220} Writer Instance Id: {007ff9de-983b-48a9-883f-ade2127496d8} State: [5] Waiting for completion Last error: No error Writer name: 'SqlServerWriter' Writer Id: {a65faa63-5ea8-4ebc-9dbd-a0c4db26912a} Writer Instance Id: {84a5452d-e3ca-4170-99f1-2423b2951868} State: [5] Waiting for completion Last error: No error Writer name: 'Windows Server Storage VSS Writer' Writer Id: {e376ebb9-f0fe-4e1a-adaa-bfbdaf3ab488} Writer Instance Id: {4299009e-a50e-4d54-a9fb-cced15c40a9e} State: [5] Waiting for completion Last error: No error Writer name: 'Registry Writer' Writer Id: {afbab4a2-367d-4d15-a586-71dbb18f8485} Writer Instance Id: {0374fd5a-a6f4-4876-bf5a-be16520f2fb1} State: [1] Stable Last error: No error Writer name: 'IIS Metabase Writer' Writer Id: {59b1f0cf-90ef-465f-9609-6ca8b2938366} Writer Instance Id: {e9436ec6-76cc-4f74-b99f-78c8d4d9a132} State: [5] Waiting for completion Last error: No error Writer name: 'FRS Writer' Writer Id: {d76f5a28-3092-4589-ba48-2958fb88ce29} Writer Instance Id: {37e00d01-cc07-47ef-b5f2-c85efdafdd89} State: [5] Waiting for completion Last error: No error Writer name: 'NPS VSS Writer' Writer Id: {35e81631-13e1-48db-97fc-d5bc721bb18a} Writer Instance Id: {cbaf3141-9918-4aac-a83d-02f518739fd1} State: [5] Waiting for completion Last error: No error Writer name: 'Shadow Copy Optimization Writer' Writer Id: {4dc3bdd4-ab48-4d07-adb0-3bee2926fd7f} Writer Instance Id: {9101c190-4512-45bb-81ed-72f641e121d4} State: [1] Stable Last error: No error Writer name: 'MSSearch Service Writer' Writer Id: {cd3f2362-8bef-46c7-9181-d62844cdc0b2} Writer Instance Id: {b7186baf-d6a4-4468-9fd3-d0d6adceef16} State: [5] Waiting for completion Last error: No error Writer name: 'TS Gateway Writer' Writer Id: {368753ec-572e-4fc7-b4b9-ccd9bdc624cb} Writer Instance Id: {26bbfec7-e41d-426b-94ed-30bf2fe049d2} State: [5] Waiting for completion Last error: No error Writer name: 'COM+ REGDB Writer' Writer Id: {542da469-d3e1-473c-9f4f-7847f01fc64f} Writer Instance Id: {70874aa8-9b4a-43ac-b0de-24fdef92974a} State: [1] Stable Last error: No error Writer name: 'IIS Config Writer' Writer Id: {2a40fd15-dfca-4aa8-a654-1f8c654603f6} Writer Instance Id: {fbb72699-4dcb-4635-9154-eb0f9f76919b} State: [5] Waiting for completion Last error: No error Writer name: 'Dhcp Jet Writer' Writer Id: {be9ac81e-3619-421f-920f-4c6fea9e93ad} Writer Instance Id: {a84a00da-e4b8-423e-ba95-6d91987e32c3} State: [5] Waiting for completion Last error: No error Writer name: 'WMI Writer' Writer Id: {a6ad56c2-b509-4e6c-bb19-49d8f43532f0} Writer Instance Id: {ecf4a9ee-0d7b-44ad-a392-f19afbcda937} State: [5] Waiting for completion Last error: No error Writer name: 'Certificate Authority' Writer Id: {6f5b15b5-da24-4d88-b737-63063e3a1f86} Writer Instance Id: {cda58328-23af-4258-b5d1-f9357373096b} State: [5] Waiting for completion Last error: No error Writer name: 'NTDS' Writer Id: {b2014c9e-8711-4c5c-a5a9-3cf384484757} Writer Instance Id: {d093c4e7-e0d1-4a4a-b0d9-62558f3fff67} State: [11] Failed Last error: Non-retryable error VSSADMIN LIST PROVIDERS C:\Users\administrator>vssadmin list providers vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool (C) Copyright 2001-2005 Microsoft Corp. Provider name: 'Microsoft Software Shadow Copy provider 1.0' Provider type: System Provider Id: {b5946137-7b9f-4925-af80-51abd60b20d5} Version: 1.0.0.7 To solve the non-retryable error, I've read that I need to reboot the server but I can't really reboot it every 5 minutes to do tests. And for the record, I've done that allready and didn't work. The CMD line for the backup (found in task scheduler) is the following: %windir%\system32\wbadmin.exe start backup -templateId:{f05558a1-e7ac-47e1-929e-df427ea5630f} -quiet The backup is configured to to a full server backup on a dedicated external Western Digital hard disk of 1TB at 10:30PM. I've read on a forum of Symantec that re-registering the VSS writers solves the issue but in my case, it didn't. This is pretty much as far as I've gotten and I've run out of ideas and places to look on the internet. Either I find a thread that has the exact same issue but no solution, or a thread that is similar but not quite and doesn't help me.

Hello, Please ask them here: http://social.technet.microsoft.com/Forums/en-US/windowsbackup/threads This posting is provided "AS IS" with no warranties or guarantees , and confers no rights. Microsoft Student Partner 2010 / 2011 Microsoft Certified Professional Microsoft Certified Systems Administrator: Security Microsoft Certified Systems Engineer: Security Microsoft Certified Technology Specialist: Windows Server 2008 Active Directory, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Network Infrastructure, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Applications Infrastructure, Configuration Microsoft Certified Technology Specialist: Windows 7, Configuring Microsoft Certified Technology Specialist: Designing and Providing Volume Licensing Solutions to Large Organizations Microsoft Certified IT Professional: Enterprise Administrator Microsoft Certified IT Professional: Server Administrator Microsoft Certified Trainer