Exchange 2007 (no-SP, SP1 and SP2) isn’t supported on Windows 2008 R2, but since SP3 it is. As my installation disc / iso only contains Exchange 2007 SP1 I had to install first this iso and then directly update it to SP3.
Installations looks to go well. But first got a warning on the hub transport: “Setup cannot detect an SMTP or Send connector with an address space of ‘*’.”.
This warning could be ignored, the only thing we have to do after installation is create a SMTP connector, more information about this read here.
But at the end of the installation the Mailbox Role Failed with error: “An error occurred. The error code was 3221684229. The message was Access is denied..”
To get the Mailbox Role installed we have to set the compatibility mode from the exchange setup.exe to Windows Server 2008 (Service Pack 1) and run the setup again and add the Mailbox Role.
Now installation goes fine.
After you finished the installation please update Exchange 2007 directly to SP3.