In the event that whatever software package you find yourself installing requires the .NET Framework 3.5, find a Windows 10 install disc or iso and follow the steps below.
- Insert the disc/mount the iso
- Open a Command Prompt with administrator privileges
- Type the following command: Dism /online /enable-feature /featurename:NetFX3 /All /Source:[disc drive/iso mount point]:\sources\sxs /LimitAccess
That should succeed where downloading the installer from TechNet or ticking the box in Windows Features fails.