在Windows2008 R2 SP1上安装Lync时，会安装失败，报如下错误：

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:\Windows\system32\dism.exe /online /norestart /add-package
/packagepath:C:\Windows\servicing\Packages\Microsoft-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:\Windows\system32\dism.exe /online /norestart /add-package
/packagepath:C:\Windows\servicing\Packages\Microsoft-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)

在Windows2008 R2上安装Lync时，安装程序会自动安装组件Windows-Media-Format，然后再安装Lync程序。

但在Windows2008 R2 SP1，lync安装程序在安装组件Windows-Media-Format时会报错导致安装失败。

这是因为升级到R2 SP1后Windows-Media-Format的版本从6.1.7600.16385变成了6.1.7601.17514，而集成在

Lync安装程序里面的调用命令是：

Executing external command: C:\Windows\system32\dism.exe /online /norestart /add-package
/packagepath:C:\Windows\servicing\Packages\Microsoft-Windows-Media-Format-
Package~31bf3856ad364e35~amd64~~6.1.7600.16385.mum /ignorecheck

所有因找不到组件而安装失败。

因此我们要在安装lync之前，先手动安装该组件并重启后再安装Lync，安装该组件命令如下：

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

KB Article 2522454: Lync Server 2010 Setup or Remove Lync Components Fails on Windows Server 2008 R2 SP1