To use Microsoft Lync Web App communications software, you must have one of the following supported operating system and Internet browser combinations. You also must have the Microsoft Silverlight 4 GDR 0 (Build: 4.0.50524) browser plug-in, or a later version of Silverlight, installed on your...
Now that there are so many different versions of Windows/Active Directory you can easily get confused to what Exchange Server version is supported on which OS/Active Directory Luckily there is a support matrix that explains this very clearly! This is a screenshot of the Active Directory Support Matrix...