The built-in DISM tool (Deployment Imaging Servicing and Management) can install features directly from a local CAB file without touching Windows Update.
dism /online /add-package /packagepath:C:\temp\netfx3.cab Download Microsoft-windows-netfx3-ondemand-package.cab
This package is version-specific . A .cab file built for Windows 10 version 1809 will not work on Windows 11. You must match the package to your exact Windows build (e.g., 21H2, 22H2, 23H2, or Windows 11 22H2/23H2). The built-in DISM tool (Deployment Imaging Servicing and
(On Windows Server, use Get-WindowsOptionalFeature -Online -FeatureName NetFx3 ) Download Microsoft-windows-netfx3-ondemand-package.cab
If you need help with a or a different version of Windows , let me know so I can give you the exact command. Install .NET Framework 3.5 on Windows 10 - Microsoft Learn