Need help with a specific error code? Check out the Microsoft .NET Setup Forum for community troubleshooting.
While modern Windows versions (10/11) typically include .NET 4.x or 5.0+, they do not always come with .NET 3.5 pre-activated. While Windows can pull this feature from Windows Update, this requires internet access and can fail due to network restrictions or corrupted system files. No Internet Required:
On modern versions of Windows, the payloads for .NET Framework 3.5 are already stored inside the original Windows installation media (ISO, DVD, or USB) in the sources\sxs directory. You can use the built-in DISM command-line tool to enable it completely offline. net framework 3.5 sp1 offline installer
Click on the corresponding result to open the Features control panel.
: Prevents Windows from trying to connect to Windows Update. 3. Enabling via Windows Features (Requires Source) Need help with a specific error code
While modern operating systems like Windows 10 and Windows 11 include .NET 3.5 as an optional feature, the default installation method requires an active internet connection to download files from Windows Update. In secure enterprise environments, offline workstations, or areas with limited connectivity, this online installation method fails.
Right-click the downloaded executable ( dotnetfx35.exe ) and select . If prompted by User Account Control (UAC), click Yes . While Windows can pull this feature from Windows
The Deployment Image Servicing and Management tool will process the package. Wait for the progress bar to reach 100% and confirm "The operation completed successfully."
Mount your Windows installation ISO or insert your Windows bootable USB drive.
