If you get this error during installation of Lync 2010 on a 2008 R2 SP1 server,
Name of prerequisite: Wmf2008R2 MM/DD/YYYY HH:MM:SS AM
Name of prerequisite: Wmf2008R2 MM/DD/YYYY HH:MM:SS AM
Type of prerequisite: exe MM/DD/YYYY HH:MM:SS AM
Method used to check prerequisite state: WmfNeeded2008R2() MM/DD/YYYY HH:MM:SS AM
Result of state check: True MM/DD/YYYY HH:MM:SS AM
Executing external command: C:Windowssystem32dism.exe /online /norestart /add-package
/packagepath:C:WindowsservicingPackagesMicrosoft-Windows-Media-Format-
Package~31bf3856ad364e35~amd64~~6.1.7600.16385.mum /ignorecheck MM/DD/YYYY HH:MM:SS AM
Installation result: -2146762496 MM/DD/YYYY HH:MM:SS AM
Error: Prerequisite installation failed: Wmf2008R2
Details
Type: PrereqInstallFailed
Stack Trace
at Microsoft.Rtc.Internal.Tools.Bootstrapper.BootstrapperTask.AddMsiPrereq(String prereqName)
at Microsoft.Rtc.Management.Internal.Utilities.LogWriter.InvokeAndLog[T](Action`1 action, T arg)
Type of prerequisite: exe MM/DD/YYYY HH:MM:SS AM
Method used to check prerequisite state: WmfNeeded2008R2() MM/DD/YYYY HH:MM:SS AM
Result of state check: True MM/DD/YYYY HH:MM:SS AM
Executing external command: C:Windowssystem32dism.exe /online /norestart /add-package
/packagepath:C:WindowsservicingPackagesMicrosoft-Windows-Media-Format-
Package~31bf3856ad364e35~amd64~~6.1.7600.16385.mum /ignorecheck MM/DD/YYYY HH:MM:SS AM
Installation result: -2146762496 MM/DD/YYYY HH:MM:SS AM
Error: Prerequisite installation failed: Wmf2008R2
Details
Type: PrereqInstallFailed
Stack Trace
at Microsoft.Rtc.Internal.Tools.Bootstrapper.BootstrapperTask.AddMsiPrereq(String prereqName)
at Microsoft.Rtc.Management.Internal.Utilities.LogWriter.InvokeAndLog[T](Action`1 action, T arg)
the reason for this is because Lync Server installation prerequisite check cannot locate the Server 2008 R2 SP1 version of Microsoft Windows Media Format.
So as a workaround for this issue you need to install Windows Desktop Experience. 🙂