A. Windows Server 2008 R2 SP1 changed the package version of the Windows Media Format runtime, and Lync setup is looking for the pre-SP1 version.

050211-lync-2010-wmf-2008-r2-error_0

The solution is to manually add the Windows Media Format runtime package from an elevated command prompt. Use the command

%systemroot%\system32\dism.exe /online /add-package /packagepath:%windir%\servicing\Packages\Microsoft-Windows-Media-Format-Package~31bf3856ad364e35~amd64~~6.1.7601.17514.mum /ignorecheck

Once the reboot is complete, restart the Lync Server 2010 installation and you'll get past the Wmf2008R2 prerequisite failure.