Windows Server 2008 Prerequisites
When installing on Microsoft Windows Server 2008, you must install .NET Framework 3.5 SP1 from the management console.
To install .NET Framework 3.5 SP1:
Right-click the Start Menu and select Administrative Tools, and then Server Manager.
In the tree on the left, click Features.
Click the Add Features link on the right.
Select the .NET Framework 3.5.1 Features checkbox.
Click Next.
Click Install.
Click Close after the installation completes.