Windows Server 2016 Installing .NET 3.5 Error – Source File Not Found Solution

Installation method: Download NetFx3.cab and place it in the C:\Windows folder (C:\Windows)

Click Start, find Windows PowerShell, right-click and run as administrator, then enter the following command:

dism.exe /online /add-package /packagepath:C:\WINDOWS\netfx3.cab

Online sources mention copying the sxs file from the sources folder of Windows Server 2016. I found it too complicated and tried to open it, but got an error – c:\windows\netfx3.cab Error: 0x80070003