Original Solution Post  http://www.mysharepointadventures.com/2011/12/unable-to-change-user-profile-service-account/  Problem So you made a mistake by trying to change the service application account for the User Profile Service Application. You try to change it back to your farm account but get an ugly error message saying: An object of the type Microsoft.SharePoint.Administration.SPWindowsServiceCredentialDeploymentJobDefinition named “windows-service-credentials-FIMSynchronizationService” already exists under the parent Microsoft.Office.Server.Administration.ProfileSynchronizationService named “FIMSynchronizationService”. Rename your object or delete the existing object. Solution This problem is quite easy to fix. As the error message clearly states, there is a job that has already been created when you tried to change the the credentials for the UPS service application previously. However, when the provisioning failed the job never ran (it is a one-time j...