As president of the Windows and Windows Live Division, Sinofsky has accountability for the overall Windows business, from development to business strategy and marketing for Windows, Windows Live and Internet Explorer.
Sinofsky has held several positions on Microsoft product teams. His most recent position was senior vice president of the Windows and Windows Live engineering group. He previously oversaw the development of the Microsoft Office system of programs, servers and services, responsible for the product development of the 2007 Microsoft Office system, Microsoft Office 2003, Microsoft Office XP, and Microsoft Office 2000.
In 1994, when the Office Product Unit was formed, Sinofsky joined the team as the director of program management, and led the design of the shared technologies in Microsoft Office 95 and Microsoft Office 97. He spent about four years as a software design engineer and project lead in the Development Tools group, where he helped lead the development of the first versions of the Microsoft Foundation Classes C++ library for Microsoft Windows and Microsoft Visual C++. He joined Microsoft in July 1989 as a software design engineer.
Sinofsky holds a master's degree in computer science from the University of Massachusetts Amherst (1989). He holds an undergraduate degree with honors from Cornell University (Arts and Sciences, 1987). In 1998, Sinofsky held the appointment of visiting scholar at Harvard Business School. He spent the fall of 2004 living in Beijing, China, working on projects in sales, marketing, and research and development.