How to install .net framework 4.0.030319 runtime on windows server 2019 standard edition?

1. Important: Make sure that your computer has the latest Windows service pack and critical updates. To find security updates, visit [Windows Update]. If you are installing on XP 64 bit or Windows 2003 you might need to install the Windows Imaging Component. The Windows Imaging Component 32 bit can be found [here] . The Windows Imaging Component 64 bit can be found [here] .
2. On this page, locate the Download button and then click it to start the download. If you want a smaller x86 only installer you can find it [here]. If you need to install on ia64 then use the ia64 installer found [here].
3. To start the installation immediately, click Run.
4. To save the download to your computer so that you can install it later, click Save.
5. To cancel the installation, click Cancel.

Instructions obtained from Microsoft download center https://www.microsoft.com/en-US/Download/confirmation.aspx?id=17718

Download link: https://download.microsoft.com/download/9/5/A/95A9616B-7A37-4AF6-BC36-D6EA96C8DAAE/dotNetFx40_Full_x86_x64.exe

From Server Manager you can add the feature here (as below)

The .NET Framework 4.5 and later versions are backward-compatible with apps that were built with earlier versions of the .NET Framework. In other words, apps and components built with previous versions will work without modification on the .NET Framework 4.5 and later versions.

https://video2.skills-academy.com/en-us/dotnet/framework/migration-guide/version-compatibility#backward-compatibility

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