Sinofsky, the key Windows evangelist and public face of Windows 8, will be replaced Julie Larson-Green, who will be promoted to lead all Windows software and hardware engineering.
Microsoft also said that Tami Reller retains her roles as chief financial officer and chief marketing officer and will assume responsibility for the business of Windows.
Both will report to CEO Steve Ballmer.
Microsoft said the changes are effective immediately, but gave no reason for Sinofsky’s departure.
"I am grateful for the many years of work that Steven has contributed to the company," Ballmer said in a statement. "The products and services we have delivered to the market in the past few months mark the launch of a new era at Microsoft.
“We've built an incredible foundation with new releases of Microsoft Office, Windows 8, Windows Phone 8, Microsoft Surface, Windows Server 2012 and 'Halo 4,' and great integration of services such as Bing, Skype and Xbox across all our products. To continue this success it is imperative that we continue to drive alignment across all
Microsoft teams, and have more integrated and rapid development cycles for our offerings."
For this part, Sinofsky added:
"It is impossible to count the blessings I have received over my years at Microsoft. I am humbled by the professionalism and generosity of everyone I have had the good fortune to work with at this awesome company.”