Microsoft-windows-netfx3-ondemand-package.cab: -extra

Standard deployment uses (Deployment Imaging Service and Management Tool):

IT admins use this file to install .NET 3.5 without an internet connection using the Deployment Image Servicing and Management (DISM) tool.

Here’s a technical write-up on the and the usage of an -Extra or similar parameter (typically associated with DISM or offline servicing tools in Windows). Microsoft-windows-netfx3-ondemand-package.cab -Extra

A more significant "extra" file has emerged in recent Windows builds, starting with Windows 11 version 24H2. Users attempting an offline installation of .NET Framework 3.5 found that the command would fail with the error 0x800f081f - CBS_E_SOURCE_MISSING . The solution was to place an file called DesktopDeployment.cab right alongside the Microsoft-Windows-NetFx3-OnDemand-Package.cab in the sxs folder. For a successful installation, both files must be present, making DesktopDeployment.cab a necessary 'extra' companion for modern Windows versions.

When a machine lacks internet access, or when setting up servers via Group Policy/System Center Configuration Manager (SCCM), standard "Turn Windows Features on or off" methods may fail. This CAB file serves as the offline payload to enable the feature. Locating the File: Users attempting an offline installation of

: Obtain the CAB from a Windows ISO that matches your OS version and architecture (x64, x86, ARM64).

: Bundles core legacy runtime structures including .NET 2.0 and .NET 3.0 components required by specialized software. When a machine lacks internet access, or when

Encountering errors during the installation is common. Here are some frequent issues and their solutions.

Net Framework 3.5 (offline) installation failure is not detected

If you want, I can produce a ready-to-run PowerShell script that accepts a CAB path (and an optional -Extra folder) to automate extraction, adding to an image or enabling on the running system.