After installing, always check for security patches, as Microsoft occasionally releases "Cumulative Updates for .NET Framework 3.5" to address modern security vulnerabilities.
Once finished, a system reboot is recommended to finalize the registration of DLLs. net framework 3.5 sp1 offline installer
Right-click the downloaded dotnetfx35.exe and select "Run as administrator." After installing, always check for security patches, as
You do not need to uninstall .NET 4.8 or .NET 5/6/7 to install 3.5. They are designed to "side-load" and run independently. always check for security patches
Enabling .NET 3.5 via "Windows Features" (The Alternative Offline Method)