Do not download random “.NET 3.5 installer” EXE files from third‑party websites – they may contain malware. Use Microsoft’s official sources (Windows media or the method below).

The progress bar will reach 100%. You should see the message: "The operation completed successfully."

Once the installation wizard or command prompt finishes, you should verify that the framework is active. Open as an administrator.

If you do not have a Windows ISO file handy, several trusted tech communities have developed free, automated scripting utilities that package the official .cab deployment files into a single click.

If you want to download the offline installer files directly, you can use the following links:

Windows couldn't connect to the internet to download source files. Use Method 2 (DISM command with local media). The source files could not be found in the specified path.

You need to tell Windows where to find the installation files. The specific file we need is usually located in the sources folder named sxs .

Downloading and installing the .NET Framework 3.5 offline installer for Windows 10 or 11 is a straightforward process. By following the steps outlined in this article, you should be able to successfully install the .NET Framework 3.5 offline installer and enable it on your system. If you encounter any issues during the installation process, refer to the troubleshooting steps provided.

If you encounter issues during the installation process, here are some troubleshooting steps:

@echo off title .NET Framework 3.5 离线安装器 echo 正在安装 .NET Framework 3.5,请稍候... DISM /Online /Add-Package /PackagePath:"%~dp0\netfx3.cab" /Quiet /NoRestart echo 安装完成,请手动重启电脑。 pause