This is the most critical step. We will use the Deployment Image Servicing and Management (DISM) tool to install the feature manually.
Before diving into the technical steps, it is important to understand why this is necessary.
While Windows 10 technically includes the files necessary to install .NET Framework 3.5, the default method relies entirely on Windows Update. If your computer is offline, has a slow internet connection, or if the Windows Update service is corrupted (a common issue), the installation will fail. install net framework 3.5 offline installer windows 10
Use this only as a last resort. For a true offline install, stick with Method 1 (DISM) or Method 3 (Standalone cached installer) below.
Open "This PC" and note the drive letter assigned to the installation media (e.g., D: or E: ). This is the most critical step
Installing .NET Framework 3.5 on Windows 10 typically requires an internet connection because the system downloads necessary files from Windows Update. However, if you are working in an environment without internet access or need to deploy it across multiple machines efficiently, you can use an method.
You must have the official Windows 10 ISO or a bootable USB drive. While Windows 10 technically includes the files necessary
You must run commands as an Administrator. Method 1: Using DISM (Command Prompt) This is the most reliable method for offline installation.
Starting with Windows 10, the only supported way to install .NET Framework 3.5 offline is by using the original (ISO, USB, or DVD). Prerequisites for Offline Installation