.NET Framework

The Microsoft .NET Framework is a common component shared by Microsoft versions of programming language compilers. The use of the .NET Framework ensures that programs compiled using .NET-compatible compilers will have the same base requirements in regard to their underlying software platform. An end user who installs these programs can meet these requirements simply by installing the version of the .NET Framework required by the program, regardless of any other customizations or changes that have been made to his computer or operating system.

WinFx

With .NET Framework version 2.0, Microsoft changed the framework platform name to "WinFx" to reflect the fact that it was a significant change from the original version of the framework. The "WinFx" name was created as a shortened version of "Windows Framework X," indicating that the framework was intended for use with Windows operating systems and that it was not simply the name of a single version of the .NET Framework. WinFx was designed to be backward-compatible with software requiring .NET Framework versions 1.0 and 1.1.

NETFx

As the .NET Framework continued to expand its scope as an underlying software platform, a new name was given to the framework starting with the release of .NET Framework 3.0. The new name, "NETFx," was intended to separate the framework as a product from the Windows family of operating systems. The name reflected back to the .NET product line while still referencing the product identity created when WinFx was released. Similar to the naming of WinFx, the NETFx name was created as a shortened version of ".NET Framework X."

The NETFx Folder

The NETFx folder is created automatically when any version of the .NET Framework 3.0 or later is installed. Files and executables within the folder are not essential for Windows to run, but may be required for programs that require a newer version of the .NET Framework. The folder should be removed if the .NET installation is uninstalled, and can be deleted manually if it is not automatically removed during the uninstallation process. Future installations of the .NET Framework will recreate the NETFx folder if it has been removed.