A Microsoft Windows developer designs, develops, tests, and debugs software applications for the Windows operating system. They utilize programming languages like C#, .NET, C++, and Visual Basic, and tools like Visual Studio. They create user interfaces, implement security measures, and integrate with databases or other systems. They may also work on updates or improvements for existing Windows applications, fixing bugs or enhancing features. They work closely with other IT professionals, such as software testers and system designers, to ensure the software meets user needs and is free of errors. Additionally, they may provide user support and documentation.