the installer from the official Microsoft link above. Close all running applications. Run dotNetFx40_Full_x86_x64.exe as Administrator. Accept the license terms.
While newer versions of Windows come with .NET pre-installed, Windows 7 often requires a manual setup or a "fix" to get these dependencies running correctly. Here is everything you need to know to get it installed and working. What is .NET Framework 4.0.30319? Download Net Framework 4.0.3019 For Windows 7 64 11 Fix
Leave a comment below with the exact error message and the app you’re trying to run. the installer from the official Microsoft link above