In another big shake up of powerful tech executives, Steven Sinofsky, the President of the Windows Division at Microsoft, is out. AllThingsD is reporting that Sinofsky is leaving amidst "growing tension between Sinofsky and other top executives". He was once seen as the heir apparent at Microsoft, someone who could possibly become CEO.

This is completely unexpected given Sinofsky's successful track record at Microsoft and dark news that absolutely stains the launch of Windows 8. Having the guy in charge of Windows 8 leave Microsoft, near the launch date of Microsoft's most important product? Not. Good. AllThingsD likens the move to Apple firing Scott Forstall:

Sinofsky, though seen as highly talented, was viewed at the top levels as not the kind of team player that the company was looking for.

Sinofsky previously worked in the Office division at Microsoft but took over as President of the Windows division after the embarrassing bungling of Windows Vista. He fixed it with Windows 7 and Windows 8. Sinofsky even had a hand of creating Outlook.com and Skydrive and was a big champion of Surface. Meaning: his resume at Microsoft was pretty fantastic and whatever happened behind the scenes had to be really serious for Microsoft to part ways with his talent.

Microsoft is saying that Julie Larson-Green will now lead all Windows software and hardware engineering and that Tami Reller, the CFO at Microsoft, will assume responsibility for the business of Windows. In a letter to Microsoft employees about the news of Sinofsky leaving, Ballmer says:

As we enter this new era, and with the successful launch of Windows 8 and Surface behind us, Steven Sinofsky has decided to leave the company. Steven joined Microsoft in 1989 as a software development engineer and has contributed to the company in many ways from his work as a technical advisor to Bill Gates, to leading the evolution of the Microsoft Office business, to his direction and successful leadership of Windows and Windows Live as well as Surface. I am grateful for the work that Steven has delivered in his time at our company.

It's a cold winter already. [Microsoft via AllThingsDAllThingsD]