The microsoft-windows-netfx3-ondemand-package.cab provides a controlled, repeatable, offline-capable method for enabling .NET 3.5 on Windows Server 2012 R2. Using DISM or PowerShell with this CAB eliminates dependency on Windows Update or the original installation DVD, making it ideal for secure, disconnected environments, legacy application hosting, and automated build pipelines.
: Insert or mount your Windows Server 2012 R2 ISO. The specific file is located at D:\sources\sxs\microsoft-windows-netfx3-ondemand-package.cab (replace D: with your drive letter). The microsoft-windows-netfx3-ondemand-package
Open or Command Prompt as Administrator. making it ideal for secure
This file contains the portable, offline source for .NET 3.5, allowing installation without mounting the full OS ISO. legacy application hosting