If you try to add .NET Framework 3.5 as an additional feature from within the Control Panel > “Programs”, you will actually not succeed to get the needed files online via Windows Update.
Reason:
Win8.1 RTM needs an updated version of .NET Framework 3.5, which is currently not available at Windows Update. Once Win8.1 will be officially released to the public, this problem will be solved.
Nevertheless it is possible to install the Win8.1 RTM compatible new version of .NET Framework 3.5, because the needed software is part of the Win8.1 RTM ISO file.
This is the way how you can get .NET Framework installed onto your Win8.1 RTM:
- Insert the Win8.1 RTM installation media (DVD or USB flash drive).
- Run the Win8.1 PowerShell as Administrator (do a right click into the left buttom corner and choose the related option).
- Enter the following command (without the quotation marks):
"dism /online /enable-feature /featurename:netfx3 /all /source:X:\sources\sxs /limitaccess"
Replace the letter “X” by the actual letter of the drive with the Win8.1 RTM source files. (DVD/USB). - Hit “Enter”.
- The installation will start and being completed automaticly.
That is all!
Have fun!
Fernando
UPDATE:
Since the final version of Win8.1 is available now for everyone, there is no problem anymore to get .NET Framework 3.5 installed by using the “Windows Update” function.