Missing .NET Framework 3.5 SP1 Page
Before proceeding, you must install this prerequisite.
To install .NET Framework 3.5 SP1
Go to the .NET Framework 3.5 SP1 download site (https://go.microsoft.com/fwlink/?LinkID=136345).
Review the information on the Web page, and then click Download.
Click Run.
Follow the instructions in the .NET Framework 3.5 SP1 Installation Wizard.
When installation is complete, click Finish.