Technical Overview: Installing .NET Framework 3.5 on Windows Server 2012 R2 Introduction
Final Checklist for Success:
Using the microsoft-windows-netfx3-onDemand-package.cab file with DISM is the most reliable method to install .NET Framework 3.5 on Windows Server 2012 R2 in disconnected or update-restricted environments. Always source the CAB directly from official Microsoft media to ensure integrity and compatibility. Technical Overview: Installing
Meaning: DISM tried to reach Windows Update and failed.
Solution: Add the /limitaccess flag to prevent online checks, or configure your local group policy: Computer Configuration → Administrative Templates → System → Specify settings for optional component installation and component repair → Enable → Alternate source path. Locate your Server 2012 R2 ISO or download
Windows Server 2012 R2 does not include the complete source files for .NET Framework 3.5 (which includes .NET 2.0 and 3.0) by default. While the Server Manager or Add-WindowsFeature can install NetFx3, they typically require access to Windows Update or the original installation media (D:\sources\sxs). It should show “Installed”
You should see:
State : Enabled
Microsoft-Windows-NetFx3-OnDemand-Package.cab to a central share.