In praise that was less than exuberant, Microsoft Chief Executive Officer Steve Ballmer wrote in a memo to employees he was "grateful for the many years of work that Steven contributed to the company."
The New York Times reported Sinofsky, after 23 years with Microsoft, was often thought to be next in line to replace Ballmer. There were two major glitches in that line of thinking, however. One is that Ballmer has not given any indication that he will retire soon. Secondly, Sinofsky was often seen as an alienating figure in the company, who had difficulty working with others.
In the past year, revenues at the company's lucrative Windows business fell 3 percent, which meant Sinofsky was only paid 60 percent of his 2012 bonus, the Times said.
Forbes Magazine said Tuesday that Julie Larson-Green, program manager for development of Windows 7 and Windows 8, will take Sinofsky's place at the head of the Windows division.
Tami Reller, meanwhile, will keep her position as the firm's chief financial officer and chief marketing officer. She will absorb the responsibilities of the business end of the Windows division, Microsoft said.