dotnetfx35.exe /passive /norestart
This is the most reliable way to force the installation without Windows Update trying to download files. net framework 2.0 and 3.0 offline installer
The .NET Framework 3.5 "Full" package includes version 3.0 and 2.0 dependencies. dotnetfx35
The .NET Framework 2.0 was released in 2005, and it introduced significant improvements over its predecessor, including a new set of APIs, improved performance, and enhanced security features. The .NET Framework 3.0, released in 2006, built upon the .NET Framework 2.0 and added new features such as Windows Presentation Foundation (WPF), Windows Communication Foundation (WCF), and Windows Workflow Foundation (WF). Isolate such machines from the internet if possible
(shows progress, no reboot):
: .NET 2.0/3.0 are out of mainstream support (ended in 2011/2015). Use them only for legacy software that cannot be updated. Isolate such machines from the internet if possible.