⬇️ Download .NET Framework 3.5 SP1 (Official Microsoft)

.NET Framework 3.5 Service Pack 1 (SP1) is a popular Microsoft software framework required to run or develop many legacy Windows applications. It includes the core runtime from earlier versions plus cumulative updates.

📦 What’s Included

  • .NET Framework 3.5 original runtime components.
  • Updates from .NET 2.0 and .NET 3.0 service packs (cumulative).
  • Compatibility support for applications built on older .NET versions.

📥 Available Downloads

Choose between online and offline installers depending on your needs:

  • Web Installer: Downloads required files during setup (needs internet).
  • Offline Installer: Full package without needing internet after download.

These installers allow you to run applications built with .NET Framework 3.5.

🖥️ Installation Tips

On modern Windows versions (10 and newer), you can also enable .NET Framework 3.5 through system features without downloading separately.

  1. Open Control Panel → Programs → Turn Windows features on or off.
  2. Select .NET Framework 3.5 (includes .NET 2.0 and 3.0).
  3. Install and reboot if prompted.

⚠️ Notes & Community Feedback

  • Some installers labeled “offline” might still request internet access for certain components on newer systems (e.g., Windows 10/11).
  • Installation can fail with errors such as 0x800F0906 or 0x800F0950; it’s often due to update or source issues. (Community reports)