For users on very recent versions of Windows 11 (Build 27965+), Microsoft has moved toward a standalone installer named DotNet35Setup.exe to simplify this process for legacy apps. Where to find microsoft-windows-netfx3-ondemand-package.cab

: If you have the full sxs folder from an ISO, you can use:

: Inside this folder, you will find the file named microsoft-windows-netfx3-ondemand-package.cab .

: The most reliable way to get the file for free is by downloading the Windows 10 or Windows 11 ISO via the Media Creation Tool .

: Once you mount the ISO or insert your installation USB, navigate to the following directory: [Drive Letter]:\sources\sxs\