By default the .Net 3.5 framework is not installed on Window 8 and 8.1. When enabling the feature it will download the needed files from Windows Update. If you have a slow or no internet connection it can be useful to install .Net Framework directly from the Windows 8 DVD.
Offline .Net Framework 3.5 Installation
- Insert the Windows 8.1 installation media
- Open an administrative cmd prompt or PowerShell
- Run the following command
Assumes Windows 8.1 media is at “d:".