Problème de désinstallation d'Exchange 2013 - "Erreur du serveur Exchange : Une installation incomplète a été détectée".

Je rencontre des problèmes pour désinstaller MSFT Exchange 2013. Tout d'abord, j'ai essayé de le désinstaller en utilisant la fonction Ajout/Suppression de programmes mais cela a échoué à mi-chemin.

Maintenant, j'essaie d'utiliser :

setup.exe /m:uninstall

Je reçois le message suivant :

Welcome to Microsoft Exchange Server 2013 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
Management tools
Client Access role: Client Access Front End service
Languages

Performing Microsoft Exchange Server Prerequisite Check

    Configuring Prerequisites                                 COMPLETED
    Prerequisite Analysis                                     COMPLETED

Configuring Microsoft Exchange Server

    Preparing Setup                                           COMPLETED
    Mailbox role: Client Access service                       FAILED
     The following error was generated when "$error.Clear();
          $CommandAppCmd = join-path $env:SystemRoot System32\inetsrv\appcmd.exe
;
          Start-SetupProcess -Name "$CommandAppCmd" -args "delete app /app.name:
`"Exchange Back End/mapi/nspi`"";
          Start-SetupProcess -Name "$CommandAppCmd" -args "delete appPool /appPo
ol.name:MSExchangeMapiAddressBookAppPool";
        " was run: "Process execution failed with exit code 50.".

     The following error was generated when "$error.Clear();
          $CommandAppCmd = join-path $env:SystemRoot System32\inetsrv\appcmd.exe
;
          Start-SetupProcess -Name "$CommandAppCmd" -args "delete app /app.name:
`"Exchange Back End/mapi/nspi`"";
          Start-SetupProcess -Name "$CommandAppCmd" -args "delete appPool /appPo
ol.name:MSExchangeMapiAddressBookAppPool";
        " was run: "Process execution failed with exit code 1168.".

The Exchange Server setup operation didn't complete. More details can be found
in ExchangeSetup.log located in the <SystemDrive>:\ExchangeSetupLogs folder.

Toute aide serait appréciée.