Avoid downloading this .cab file from unofficial "driver fix" websites. These files are version-specific; using a file from a different build of Windows (like Windows 10 or Server 2019) can cause system instability or security vulnerabilities. How to Install .NET 3.5 Using the CAB File
The safest and most reliable way to get this file is from the official Windows Server 2016 installation media (ISO). Avoid downloading this
Once you have the file or the path to the SxS folder, use one of the two methods below to complete the installation. Method 1: Using PowerShell (Recommended) Avoid downloading this
Always keep a copy of the Server 2016 ISO on your management server or a network share for future feature additions. Avoid downloading this