If you don't have an ISO, you can use a pre-packaged offline installer created by community experts that utilizes the official CAB files dotNetFx35W10 . Steps to Install:
The safest and most official "offline installer" payload for .NET Framework 3.5 is already inside your official Windows 10 or Windows 11 installation media (ISO file or USB boot drive). It lives inside a folder named sources\sxs . Prerequisites If you don't have an ISO, you can
Microsoft does not offer a simple "click-to-download" EXE for the offline version, but they do legally distribute the necessary component via the Visual Studio Subscription or the Microsoft Update Catalog. If you don't have an ISO
Locate your Windows 10 or Windows 11 in File Explorer. Right-click the ISO and select Mount . If you don't have an ISO, you can