Installing Office Communications Server 2007 R2 on Windows Server 2008 R2 RTM, works fine, but there are a few manual changes that needs to be made before everything runs smooth
First there is the .Net Framework 3.5 witch is normally a port af the Installation process of OCS 2007 R2 setup.exe file. In Windows Server 2008 R2 the Framework is a feature and needs to be installed by the “add Feature” wizard.
Also the Windows Media Format Runtime is normally installed by the setup, but this part is more tricky. You need to install this package from the OS software repository
In my version of Windows Server 2008 R2 (Standard Edition) the command was as follow:
pkgmgr.exe /ip /m:”C:WindowsservicingPackagesMicrosoft-Windows-Media-Format-Package~31bf3856ad364e35~amd64~~6.1.7600.16385.mum”
Run this command from the Command Prompt on the Windows Server that you intend to use as a front end server