Azure Pack: Web Sites MBCA 2.0 Model preventing Feature Pack for Windows Azure Pack Web Sites v2 (KB2927682) from installing.

Windows Update is failing to install “Feature Pack for Windows Azure Pack Web Sites v2 (KB2927682)” on one of my Azure Pack servers. And just give the error message: 0x80070643

The event log shows a slightly better error message; “Product: Web Sites Local Feed — A newer version of Web Sites Local Feed was found on this machine.”

After further investigation, the MSI Logfile reveals some great information and clues;

It lists a program with GUID {BE2AD1F0-C5FF-4F62-95BD-44C829150573} that prevents the installation from completing.
And that GUID turned out, after a quick Registry search, to be “Web Sites MBCA 2.0 Model”.

And after uninstalling “Web Sites MBCA 2.0 Model” from Add/Remove Programs, my Windows Update installation went through at once!

Success!