. In modern Windows versions (10 and 11), this framework is considered a "Feature on Demand" (FoD) and is not pre-installed to save disk space. Microsoft Learn Why You Need This File
This feature allows users to install the .NET Framework 3.5 components on-demand, rather than having to install the entire .NET Framework 3.5 package. The Microsoft-windows-netfx3-ondemand-package.cab file contains the necessary files for this on-demand installation. Microsoft-windows-netfx3-ondemand-package.cab -Extra
The Microsoft-windows-netfx3-ondemand-package.cab file is essential for several reasons: use the following command: powershell
It includes the runtime engines for both .NET 2.0 and 3.0. Microsoft-windows-netfx3-ondemand-package.cab -Extra
These errors indicate that DISM cannot find the source files or the .cab file is corrupted.
If you have copied the CAB file to a local folder (e.g., C:\Sources ), use the following command: powershell