Prerequisite check for system component .NET Framework 3.5 SP1 failed with the following error message:
".NET Framework 3.5 SP1 requires manual activation on Windows 8 and Windows Server 2012"
See the setup log file located at 'C:\Users\xxx\AppData\Local\Temp\VSDFD80.tim\install.log' for more information
(sigh) Not that complicated, but the issue is remembering what to do to install the 3.5 Framework.
Screen shots below : )