The article outlines the process of using CircleCI's Windows execution environment to build and test a simple calculator application developed with ASP.NET Core on a Windows virtual machine. It provides a detailed breakdown of the configuration file used for the application, highlighting the benefits of CircleCI's Windows support, such as Docker Engine support, build isolation, and access to various powerful features like caches and workspaces. The text explains the steps to set up and run tests using the Windows executor, preloaded with Visual Studio 2019, and emphasizes the importance of unit testing and code coverage collection. Additionally, it describes the workflow of test and build jobs, detailing how the build job requires all tests to pass before execution. The use of CircleCI orbs is highlighted as a time-saving approach that simplifies configuration with fewer lines of code, enhancing ease of understanding and maintenance. The article concludes by advocating the efficiency of CircleCI's Windows executor, ensuring seamless build and test processes for ASP.NET Core applications.