In Microsoft's executive offices, Sinofsky gets credit for keeping the wheels of two of Microsoft's biggest engines running. Questions about products with soul or technological innovation become less pressing when his Windows division generates $12.2 billion in annual operating profit on sales of $19 billion, as it did in the last fiscal year. When it comes to upgrading existing products, quality control can often trump creativity.
That success has increased Sinofsky's power within Microsoft. He increasingly is seen as one of the few executives not just at Microsoft, but anywhere, who can successfully marshal a massive team to release a product as complex as Windows. It's Microsoft's moonshot, a multi-year endeavor on which more than 4,000 workers toil.
"They need him," said one former senior executive.
"The general perception is that the Windows group is harder to work with over the past year than it has been," a current Microsoft executive said.
As Windows 8 rolls out, speculation both inside Microsoft and out runs high that Sinofsky may be in line to take Ballmer's job as chief executive when he eventually moves on. After all, Sinofsky has run the two marquee products at Microsoft, Windows and Office. He has a track record of shipping on time, a highly valued skill at the company.
What's more, many of the would-be rivals for the job, senior executives who have also run the biggest Microsoft groups, have left the company in recent years. Jeff Raikes, who ran the Office group and Microsoft's sales operation, is now chief executive of the Bill & Melinda Gates Foundation. Robbie Bach, who led Microsoft's entertainment division, retired. Kevin Johnson, who led the Windows division and Microsoft's sales force, is now chief executive of Juniper Networks. And J Allard, a younger leader who launched the Xbox business and led the skunkworks tablet concept Sinofsky opposed, left the company in 2010.
That would seem to clear the decks for Sinofsky's ascension. But a Microsoft executive familiar with the thinking of senior management said Sinofsky's rise to the corner office is hardly a sure thing. Senior managers recognize how divisive Sinofsky can be. He may well be the right guy to get Windows out the door, but his temperament may not be suited to run a giant and iconic corporation.
Increasingly, the company is connecting products across divisions, letting consumers, for example, pick songs over Xbox-connected home entertainment systems using Windows 8 tablets. It's a world that requires the kind of cross-division teamwork that Sinofsky's critics say he lacks.
"Steven is a rare talent," the executive said. But "as you think about future leadership, collaboration will be critical in a way it has never has before."