One of my customers had installed Workflow Manager 1.0 but while uninstalling it, he was encountering the mentioned below error:
This computer is part of a farm. To uninstall, first leave the farm either using 'Leave from Farm' option in Configuration Wizard or Remove-WFHost cmd-let in PowerShell. 

 

When we tried to execute the command Remove-WFHost, we were getting the following error:
remove-wfhost : Ceritificate requested with thumbprint {GUID} not found in the certificate store

 

Resolution:

We executed the following steps to resolve the issue. 

  1. Deleted the following registry hives: 

HKLM\Software\Microsoft\Workflow Manager
HKLM\Software\Microsoft\Service Bus

        2.  Deleted the following databases:

SbGatewayDatabase
SbManagementDB
SBMessageContainer01
WFManagementDB
WFResourceManagementDB
WFInstanceManagementDB

       3.  Uninstalled CU1 for Workflow Manager 1.0 and CU1 for Service Bus 1.0 from Control Panel

       4.  Uninstalled Workflow Manager 1.0, Workflow Manager Client 1.0 and Service Bus 1.0 in the order mentioned (Refer: http://technet.microsoft.com/en-us/library/jj193489.aspx)

       5.  Rebooted the machine hosting WFM 1.0
 

Written by:
Kshitij Dattani

Reviewed by:
Shashidharan Krishnan 

Microsoft India GTSC