In an unexpected twist, last night Microsoft announced that its top executive in charge of Windows software, Steven Sinofsky, will be leaving the company effective immediately.

Just last month Sinofsky had been one of the most visable faces at Microsoft, presiding over the launch of the massively anticipated Windows 8 OS as well as the company's new Surface tablet. But now he is out, to be replaced by Julie Larson-Green and Tami Reller who will oversee Windows engineering and business operations, respectively.

Sinofsky's ouster comes just weeks after Apple's iOS chief Scott Forstall was vanquished from the company in a similar corporate shake up. Like Forstall, Sinofky's downfall is said to have been caused by his difficult personality and inability to get along with other executives.

In an internal memo, Microsoft CEO Steve Ballmer framed Sinofsky's departure as a voluntary move.

"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," he writes.

Sinofsky joined Microsoft way back in 1989 and took over as Windows chief in 2006. After the unfortunate launch of Windows Vista, Sinofsky spearheaded the quick development of the much-better-received Windows 7, which saved the company's reputation. The fate of Windows 8, a radical departure which debuted late last month, remains to be seen.

“It is impossible to count the blessings I have received over my years at Microsoft,” Sinofsky said in his own statement. “I am humbled by the professionalism and generosity of everyone I have had the good fortune to work with at this awesome company."

[via AllThingsD]