Additionally, if you don't want to download the whole Redistributable package from Microsoft (thus skipping steps 1-3), download only the CAB file for .NET Compact Framework 3.5 from MoDaCo.

Turn Windows Features on or off Uninstall Microsoft .NET Framework 4.6 or higher Use the DISM command to install Microsoft .NET Framework 3.5 Download .NET Framework 3.5 from the official website ...

Offline installation of the .Net 3.5 framework from the Windows 8 Disk. In some cases the framework is included with the installation disk that comes with Windows.

Yesterday, Microsoft posted the final version of the .NET Framework 3.5 to its download site, as well as several updates to other .NET Framework versions.