There are certain software components that don't work as applications by themselves, but rather as a framework to run other apps.

This is the case of Microsoft .NET Framework, a software package that contains everything you need to execute programs based on the .NET development environment. It includes common library files, language common routines and ASP.NET files.

This component will fix all the error messages you may get when trying to run .NET applications, so you should definitely install it on your system. What's more, installation is really easy: simply run the file and follow the wizard's steps. Just don't expect to have an interface or something similar to run .NET Frameworks: there's simply none.

Microsoft .NET Framework is a necessary component to run many applications nowadays, so you should absolutely install it on your system.