How to continue a failed Exchange uninstall

If you receive an error during an uninstall that is never a good thing. But what happens when you clear the error and Exchange is in a partially uninstalled state. Restarting the uninstall from Control Panel > Programs and Features may result in an error like this.

An incomplete installation was detected. Run setup to complete Exchange installation.

To uninstall you are going to need the Exchange installation ISO. Once you have the ISO mounted open an elevated command prompt and change to the ISO drive letter (e.g. “cd D:”). Then run the following command.

D:\> setup.exe /mode:uninstall

The mode parameter allows you to specify the installation method. In our case, we specify we want to perform an uninstall. You can read about the various parameters in the following article.

The Exchange uninstall will then pick up where it left off. In my case, the Exchange installation failed during the removal of the Transport Services. The Mailbox and Client Access roles had already been successfully removed, so that is where it picked back up.

Microsoft Exchange Server 2013 Cumulative Update 23 Unattended Setup
Mailbox role: Mailbox service
Mailbox role: Unified Messaging service
Mailbox role: Client Access service
Mailbox role: Transport service
Client Access role: Front End Transport service
Client Access role: Client Access Front End service
Languages

Performing Microsoft Exchange Server Prerequisite Check

   Configuring Prerequisites                            COMPLETED
   Prerequisite Analysis                                COMPLETED

Configuration Microsoft Exchange Serve

   Preparing Setup                                      COMPLETED
   Mailbox role: Transport Services                     COMPLETED
   Client Access role: Front End Transport service      COMPLETED
   Client Access role: Client Access Front End service  COMPLETED
   Languages                                            COMPLETED
   Stopping Services                                    COMPLETED
   Removing Exchange Files                              COMPLETED
   Restoring Services                                   COMPLETED
   Finalizing Setup                                     COMPLETED

The Exchange Server setup operation completed successfully.

With the uninstall of Exchange complete you can now continue with the remainder of your decommission process.

Have you seen this issue before? What did you do to fix it? Drop a comment below or join the conversation on Twitter @SuperTekBoy