: Circa November 2006 (Original .NET 3.0 Release).

is a highly capable Microsoft technology that provides an API, an in-process engine, and a designer to implement long-running processes as workflows within .NET applications.

That specific file version might come from:

For modern development, Windows Workflow Foundation is typically installed as a component of Visual Studio Open Visual Studio Installer : You can do this through your Start menu or by selecting Tools > Get Tools and Features Visual Studio Select Individual Components : Click on the Individual components tab at the top of the installer window. Find the WF Component : Scroll down to the Development activities Select and Modify : Check the box for Windows Workflow Foundation to start the installation. Troubleshooting Common Issues

Because WF 3.0 is a component of the .NET Framework 3.0, it is typically installed by enabling the framework or its newer counterparts that include it (like .NET 3.5).