The built-in DISM tool (Deployment Imaging Servicing and Management) can install features directly from a local CAB file without touching Windows Update.
@echo off dism /online /add-package /packagepath:\\server\share\netfx3.cab /quiet /loglevel:1
This often means the CBS manifest is locked, or the system is in a pending restart state.
This method adds the CAB file directly as a package and is sometimes more effective when encountering persistent errors. Download Microsoft-windows-netfx3-ondemand-package.cab
Legacy software, corporate applications, and older video games often require this specific framework to launch. While Windows can usually download these components automatically via Windows Update, network restrictions, firewalls, or air-gapped environments frequently require system administrators and power users to look for a way to for offline deployments. Why Is the .NET Framework 3.5 CAB File Necessary?
This is the most common error. It means the source files could not be found.
CAB is a Windows Cabinet file, which is a compression archive used for software distribution by Microsoft. The built-in DISM tool (Deployment Imaging Servicing and
Alternative Deployment Option: If you mounted a Windows ISO directly and it is assigned to drive letter D: , you can point DISM straight to the drive without moving files:
Since Microsoft does not host the legacy netfx3 .cab file as a direct, standalone web download, you have to extract it from the official Windows installation media. Here is how you securely get it: Method 1: Extract from a Windows ISO (Recommended)
If you are still receiving the error, it often means: The CAB file you downloaded is corrupted. This is the most common error
Here is the step-by-step guide to getting .NET 3.5 working again in under 5 minutes.
You must run the command prompt with Administrator privileges.