Exchange 2010: Installation of Service Pack 2 not possible

The following problem has occurred during the installation of Service Pack 2 for Exchange Server 2010:

Remove Exchange files
Error

Error:
Das Produkt mit dem Code 4934d1ea-be46-48b1-8847-f1af20e892c1 kann nicht entfernt werden. Schwerwiegender Fehler bei der Installation. Fehlercode: 1603. Letzter vom MSI-Paket ausgegebener Fehler: ‚Fehler beim Schreiben in die Datei C:\Config.Msi\818feddf.rbf.  Überprüfen Sie, ob Sie auf dieses Verzeichnis zugreifen können.‘.

Serious error during installation
Hier klicken, um die Hilfe aufzurufen … http://technet.microsoft.com/de-DE/library/ms.exch.err.default(EXCHG.141).aspx?v=14.2.247.1&e=ms.exch.err.Ex14D022&l=0&cl=cp

Elapsed time: 00:01:59

This error appears in the event log:

Source: MsiInstaller
ID: 11310
Produkt: Microsoft Exchange Server — Error 1310. Fehler beim Schreiben in die Datei C:\Config.Msi\819be273.rbf.  Systemfehler 5. Überprüfen Sie, ob Sie auf dieses Verzeichnis zugreifen können.

The installation of the service pack is canceled and the services are not restarted.

The errors indicate a problem with the Windows Installer, unfortunately in my case the suggested solutions for Event ID 11310 did not work. The error occurred again and again. Possibly in connection with other software that was installed on the Exchange Server, but this could not be clarified conclusively.

To install Service Pack 2, it helped to search for the strings in the registry and delete them. In this example, I searched for the string “4934d1ea-be46-48b1-8847-f1af20e892c1” under the key "HKLM\Software\Microsoft\CurrentVersion\Installer\UserData\S-1-5-18\Products" searched for. To be on the safe side, I exported the key beforehand and then deleted it.

The error message then occurred 2 more times, but with different keys, after these keys were also deleted, the setup ran cleanly. However, Setup asked for a language pack from Service Pack 1 during the installation. The file could be selected and Setup completed the update.