Use the offline installer (full package) and disable your antivirus temporarily during install. Also, ensure the Windows Update service is running (set to Manual).
Here are the legitimate download URLs for .NET Framework 4.0 (Build 4.0.30319): net framework 4.0 319 download
Yes, but with a critical caveat: Microsoft no longer supports .NET Framework 4.0. It has been superseded by 4.5, 4.6, 4.7, and 4.8. However, the original installers are still available through Microsoft’s official download center for legacy purposes. Use the offline installer (full package) and disable
For environments without internet access, Microsoft provides a Standalone Installer Recommended Version: and 4.8. However