Attempting to install .NET Framework 3.5 on Windows 8.1 using the “Add Windows Features” dialog and received the following error.
Windows couldn't complete the requested changes. Windows couldn't connect to the Internet to download necessary files. Make sure that you're connected to the Internet, and click "Retry" to try again. Error code 0x800F0906
This seems to be caused by Group Policy setting restricting Windows Update to a local WSUS server.
To get around this, create the following registry key:
This key will only affect the loading of new features, it won’t prevent the PC from pulling updates from WSUS.