Verify that the source files exist on the media. Navigate to the mounted drive and open the folders: [Drive Letter]:\sources\sxs . You should see a file named microsoft-windows-netfx3-ondemand-package~31bf3856ad364e35~amd64~~.cab . Step 3: Run the DISM Command

Many older software applications, legacy business tools, and classic PC games require the to run on modern operating systems. While Windows 10 (64-bit) comes pre-installed with newer versions like .NET Framework 4.8, it does not always have version 3.5 enabled by default.

Verify that the drive letter in your DISM command perfectly matches your mounted ISO. Ensure the Microsoft-Windows-NetFx3-OnDemand-Package~... file exists inside the sources\sxs folder of your installation media. Error Code 0x800F0954

This is the recommended method. It uses Windows' built-in Deployment Image Servicing and Management (DISM) tool, which comes with all modern versions of Windows. It is incredibly fast and reliable because it pulls the necessary files directly from a Windows 10 installation ISO, completely bypassing the need for an internet connection.

"But I don't have a DVD drive," Leo said.

remains an essential component for running many legacy desktop applications on Windows 10 64-bit systems. While newer versions like .NET Framework 4.8 come pre-installed, certain older software and games specifically require version 3.5 (which includes .NET 2.0 and 3.0) to function.

This is the standard "offline" method used by IT professionals. It utilizes the Windows Component Store ( WinSxS ) found within the Windows 10 installation media (ISO or USB). This method is preferred because it installs the exact version of .NET 3.5 designed for your specific version of Windows 10, ensuring maximum compatibility.

Before we begin, there are just a couple of things to prepare. This will make the installation process smooth and error-free.

by typing cmd in the Windows search bar, right-clicking the result, and selecting Run as administrator .

Look at the top of the list for .

DISM /Online /Add-Package /PackagePath:C:\Windows\netfx3.cab

If you do not have Windows 10 installation media, you must download the official offline executable file from Microsoft using a device that has internet access. You can then transfer this file to your offline 64-bit Windows 10 PC via a USB flash drive.

, Windows 10 and 11 users often face challenges when trying to install this specific version without an active internet connection. Because .NET 3.5 is considered a "Feature on Demand," the most reliable offline installation method requires using the original Windows 10 installation media as a source. The Role of Installation Media