Microsoft's executive shakeup: Windows head Steven Sinofsky departs, the full story

Steven Sinofsky, who led Microsoft's Windows division before abruptly leaving the company in late 2012, is dipping a toe into the world of startup investing. This morning, Sinofsky announced on his blog that he was joining Andreessen Horowitz, one of the biggest venture capital firms in Silicon Valley. "I'm relatively new to the VC world and have a lot of learning to do — and I am very excited to do that," he writes. Sinofsky served as Windows team president starting in 2009, after two decades at Microsoft, but since his departure he's launched a productivity and development blog called "Learn by Shipping" and begun a teaching stint at Harvard Business School.

Sinofsky writes that he became acquainted with firm founders Marc Andreessen and Ben Horowitz late last year, and he's become interested in moving into venture capital. He's not, however, going to be joining the firm full-time. He'll serve instead as a "board partner," a position that will let him periodically join the boards of companies that receive funding from Andreessen Horowitz. While Sinofsky was frequently described as a laser-focused, sometimes abrasive Windows head, we're told that his new role will be open-ended, as he moves between various startups and the core Andreessen Horowitz team.

Former Windows and Windows Live president Steven Sinofsky abruptly left Microsoft late last year shortly after the company shipped Windows 8. As the head of Windows, Sinofsky played a vital part in shipping Windows 7 and Windows 8 on time. He is now turning his attention to writing a blog about product development and management after announcing his plans to teach at Harvard Business School.

The new blog, entitled Learn by Shipping, will see Sinofsky return to his habit of documenting processes and decisions around product management. Sinofsky wrote a number of lengthy articles during the Windows 7 and Windows 8 development phases and Learn by Shipping "picks up where these blogs leave off" he says. Those who are hoping he might shed some light on his Microsoft departure will be left disappointed. Sinofsky says "this blog won’t be about specifics or the past regarding Microsoft."

It's been a little over a month since Windows and Windows Live president Steven Sinofsky abruptly left Microsoft due to apparent clashes with management, but now we know his next move. According to his Twitter account, Sinofsky will be teaching at the Harvard Business School this spring, something he did prior to joining the Windows team. A follow-up tweet indicated that he'll be teaching courses related to product development. It's not clear yet if this is a single-semester deal or whether Sinofsky plans to stick around Harvard, but his extensive experience at Microsoft developing Windows 8 (among other products) should make for an interesting class next semester, to say the least.

Former chief of Windows, Steven Sinofsky, departed Microsoft earlier this week in a shock announcement following the release of Windows 8 and Surface RT. While sources have claimed his departure was related to a clash of personalities, Sinofsky has started to share some insight into his role at Microsoft.

In a blog post by Hal Berenson, a former Microsoft distinguished engineer, Sinofsky has replied in the comments section to dispute some facts around rumored internal battles. Berenson claimed in his post that Sinofsky had lost recent attemps to control Windows Phone and Microsoft's developer division. "I never initiated any discussions to bring together the organizations/products you describe," says Sinofsky. "No one ever approached me to manage them as part of Windows 7 or 8."

Microsoft's Andy Lees, who was moved out of the top Windows Phone job less than a year ago, has been shifted to the head of corporate development and strategy at the software giant, a company spokesperson has confirmed. Lees, who has been working on "a time-critical opportunity focused on driving maximum impact in 2012 with Windows Phone and Windows 8" for the past 11 months, will now report directly to Microsoft CFO Peter Klein rather than Steve Ballmer.

The timing follows a swift departure by former Windows head Steven Sinofsky, who left Microsoft due to a clash of personalities according to sources. Andy Lees originally oversaw Windows Phone and Microsoft's failed Kin devices, but has since been working closely on a deal with Barnes & Noble to bring a reader app to Windows 8. Microsoft promised an "imminent launch" of that very application back in early October, but there is still no sign of it in the Windows Store today. Lees has clearly completed his work in this area in one way or another, so we'd expect to see the app arrive shortly.

Steven Sinofsky is out at Microsoft. The Windows boss has left the building, and now Julie Larson-Green is in charge. She is now responsible for leading all Windows software and hardware engineering, and she will report to Steve Ballmer from here on out.

Running the Windows team is a huge job, but who exactly is Julie Larson-Green?

Paul Thurrott's Supersite for Windows has posted Steven Sinofsky's full letter to Microsoft employees announcing his departure. Sinofsky says that, following the Windows 8 and Surface launch, he has "decided to leave the company to seek new opportunities that build on these experiences."

This contrasts with what The Verge has heard from sources within Microsoft, which have attributed Sinofsky's exit to an abrasive personality that was seen as an obstacle to collaboration despite the man's undoubted talents. Our sources wouldn't call the departure a firing, but together with earlier reports of Sinofsky's reputation it does seem clear that many at Microsoft will be happy to move forward without him. Time will tell if new Windows head Julie Larson-Green proves easier to work with.

The abrupt departure of Windows and Windows Live President Steven Sinofsky this evening has surprised many in the Microsoft community considering that he's hot off the launch of Windows 8 and Surface, two of Redmond's most important products in the last decade. There had been persistent rumblings that the man who oversaw the launch of Windows 8 was in line for a larger role in the company, perhaps even as the heir to CEO Steve Ballmer. However, multiple sources within Microsoft describe Sinofsky as abrasive and off-putting, aggressively maintaining his control over products and putting up roadblocks for products that would have any potential to diminish the Windows (and therefore his) power — an attitude rumored to be shared by Apple's recently-deposed iOS chief Scott Forstall.

Critically, Sinofsky was not ousted because of any issues with the launch of Windows 8 or the Surface, sources tell us; in fact, it's possible that his departure was already planned, but his ability to execute on Windows 8's retail release was seen as an asset worth keeping him around long enough to see it through. But his attitude (and skill set) as an aggressive, tightly-siloed Windows boss — not a holistic Microsoft boss — may have done him in. Given that the future of Microsoft's ecosystem would require tight collaboration between disparate divisions, Sinofsky's future path as an executive at Microsoft was essentially at an end.

We've just learned that Windows chief Steven Sinofsky has left Microsoft, less than a month after the Windows 8 and Microsoft Surface launch. Here's what CEO Steve Ballmer had to say about the executive departure: