Proceed to the page and check .NET Framework 3.5 Features .
Once the command completes successfully, the installation is done! It's always good practice to restart your server to ensure all components are fully registered and the change is properly applied.
The safest and most reliable source for this file is the installation media you used to build the server. Proceed to the page and check
Mount the image onto the target server. Open the mapped drive letter (e.g., D: ). Navigate to the \sources\sxs\ directory.
To install .NET Framework 3.5 on Windows Server 2012 R2 using the microsoft-windows-netfx3-ondemand-package.cab The safest and most reliable source for this
To install .NET Framework 3.5 on Windows Server 2012 R2, you need the file, which is typically found on the original installation media. Because this feature is a "Feature on Demand," the required files are not pre-cached on the server's local drive and often fail to download automatically via Windows Update. Where to Get the CAB File
This guide addresses how to obtain and install the .NET Framework 3.5 feature on Windows Server 2012 R2, specifically focusing on the "Feature on Demand" method (using the .cab file) which avoids the need for Windows Update internet access. Navigate to the \sources\sxs\ directory
Although .NET 3.5 often installs without a reboot, some dependent features may require it. Always plan a restart during a maintenance window.
The safest and most definitive way to obtain the microsoft-windows-netfx3-ondemand-package.cab file is directly from your original OS installation media: Installing .Net 3.5 on Windows 2012 R2 - Server Fault