Exchange 2013 Upgrade/Uninstall fails while uninstall Search Foundation for Exchange

The following error was received when perming an Uninstall of Exchange 2013

"Error occurred while uninstalling Search Foundation for Exchange.System.Exception:
Cannot determine the product name registry subkey, neither the 'RegistryProductName'
application setting nor the 'CERES_REGISTRY_PRODUCT_NAME' environment variable was set."
catch{
  $deleteErrorMsg = "Failure cleaning up SearchFoundation Data folder. - " + $dataFolderPath + " - " + $_.Exception.Message;
  Write-ExchangeSetupLog -Error $deleteErrorMsg;
  }
 
as run: "Error occurred while uninstalling Search Foundation for Exchange.System.Exception: Cannot determine the product name registry subkey, neither the 'RegistryProductName' application
setting nor the 'CERES_REGISTRY_PRODUCT_NAME' environment variable was set at Microsoft.Ceres.Common.Utils.Registry.RegistryUtils.get_ProductKeyName() in n:srcsearchfoundationCommonUtilsRegistryRegistryUtils. at Microsoft.Ceres.Exchange.PostSetup.DeploymentManager.DeleteDataDirectory() at Microsoft.Ceres.Exchange.PostSetup.DeploymentManager.Uninstall(String installDirectory, String logFile) at CallSite.Target(Closure,CallSite,Type,Object,Object )"- System.Management.Automation.RuntimeException:
 Error occurred while uninstalling Search Foundation for Exchange.System.Exception: Cannot determine
 the product name registry subkey, neither the 'RegistryProductName' application setting nor the 'CERES_REGISTRY_PRODUCT_NAME' environment variable was set
 at Microsoft.Ceres.Common.Utils.Registry.RegistryUtils.get_ProductKeyName() in n:srcsearchfoundationCommonUtilsRegistryRegistryUtils.
 at Microsoft.Ceres.Exchange.PostSetup.DeploymentManager.DeleteDataDirectory()
 at Microsoft.Ceres.Exchange.PostSetup.DeploymentManager.Uninstall(String installDirectory, String logFile)
 at CallSite.Target(Closure , CallSite , Type , Object , Object )
 at System.Management.Automation.PowerShell.EndInvoke(IAsyncResult asyncResult)
 at Microsoft.Exchange.Configuration.MonadDataProvider.MonadPipelineProxy.
 .ClosePipeline(MonadAsyncResult asyncResult)

Details:
———
After installation of Exchange 2013 Installer process set the CERES_REGISTRY_PRODUCT_NAME
variable under user variables. when it fails to set this variable Exchange server 2013 cannot connect
to search engine and other issues may be experienced .

Error will occur if Environment variable CERES_REGISTRY_PRODUCT_NAME is not properly
set prior to launch installer or Uninstaller. To list all the environment variables use :

Get-Childitem env: ( Or Dir Evn: )
To display values of the CERES_REGISTRY_PRODUCT_NAME environment variable, it is
missing because of which Exchange uninstall process is failed.
For Example :

To resolve the issue , run following command to set the values for CERES_REGISTRY_PRODUCT_NAME

$env:CERES_REGISTRY_PRODUCT_NAME = “Search Foundation for Exchange”