Exchange 2016: This app cannot be run on the PC

Holger encountered a strange error during the installation of Exchange 2016 on Windows Server 2012 R2. The following error message appears immediately after starting Setup.exe:

This app cannot be run on the PC Please contact the software publisher to find a suitable version for your PC.

Well, that would be Microsoft, that makes it easier :-D But if you don't feel like contacting Microsoft now, you can read on.

Setup logs are written in the C:\ExchangeSetupLogs folder, where you will find the crucial information:

[10.11.2015 10:30:59.0714] [0] Der Registrierungsschlüssel „HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ExchangeServer\V15\Setup“ wurde nicht gefunden.

That's right, the key doesn't exist:

Es wäre ja auch zu einfach wenn das Setup.exe den Schlüssel einfach anlegt, dafür ist es ja ein Setup, dass scheint aber nicht der Fall zu sein. Dann wird der Schlüssel mit dem Namen „Setup“ eben manuell erstellt:

Now Setup.exe starts again

The content of the key looks like this after installation:

So in case an app doesn't want to start somewhere during the installation ;-)