If you regain internet access, you can enable it through the interface:
To understand why Microsoft designed .NET Framework 3.5 this way, you need to look back at the evolution of the framework. Net Framework 3.5 Includes 2.0 And 3.0 Download Offline
The Microsoft .NET Framework is a core software development platform for Windows operating systems. A persistent point of confusion for system administrators and developers is the relationship between versions 2.0, 3.0, and 3.5. This paper clarifies that .NET Framework 3.5 is not merely an incremental update but a cumulative package that includes the full binary sets of versions 2.0 and 3.0. It further explores the technical necessity, acquisition methods, and offline installation procedures for this combined framework, especially in modern Windows environments where the feature is disabled by default or requires source media for installation. If you regain internet access, you can enable
That is a misleading error message. Once .NET 3.5 is installed, legacy apps for 2.0 and 3.0 will run. You do not need to install them separately. This paper clarifies that
Avoids "Error 0x800F0906" or "0x800F081F" often caused by Windows Update connectivity issues. How to Enable .NET 3.5 Offline (The Best Methods) Method 1: Use the Windows Installation Media (CMD)