It remains to be seen whether the Microsoft reorganization announced by CEO Steve Ballmer this morning can rejuvenate the once-mighty software company. But one thing is crystal clear: The reshuffling marks another huge win for Julie Larson-Green, the 20-year company veteran whose pluck and team spirit helped her rise from rejected applicant to steward of Microsoft’s core mission.

The reorg, outlined in a series of memos obtained by AllthingsD, puts Larson-Green, formerly co-leader of Windows, in charge of all hardware devices, games, music, and entertainment. That portfolio of devices and services puts her at the epicenter of Microsoft’s predominant goal to become “a devices and services company,” as Ballmer put it in an October letter to shareholders.

Today’s promotion is just the latest leap for Larson-Green. Most recently, she replaced her longtime boss and mentor, Steven Sinofsky, to become engineering head of Windows this past November, jumping two rungs up the ladder. Unlike the notoriously prickly Sinofsky, Larson-Green is known for her communication skills and ability to work well with others, uniting people, including those outside her own purview, around a common goal.

But if you step back a bit, her biography has been a story of tenacity and persistence in pursuit of a closely-held personal mission to reshape how the world uses computers, according to various press reports, public appearances by Larson-Green, and Microsoft in-house media.

Would she replace CEO Steve Ballmer? 'I wouldn’t rule it out, but I’m not in a hurry.'A native of the northern Washington town of Maple Falls, near the Canadian border, Larson-Green took to math as a child and wrote in her high school yearbook that she wanted to work at a computer company, even though she had yet to use a computer. After enrolling at Western Washington University – where her father was a student and where her grandfather had once worked as a maintenance worker – Larson-Green had to temper her interest in digital devices. Waiting tables to make ends meet meant that Larson-Green couldn’t hit the computer labs at night, when they were open to undergraduates, so she switched her major from computer science to business administration.

The change-up seemed to lead Larson-Green into an inauspicious start: She received a rejection letter from Microsoft, already a local powerhouse and big player in the national PC market, settling instead for a tech support job at Aldus, a nascent Seattle-based maker of desktop publishing software. In the end, answering calls from angry customers for 10 months may have given Larson-Green a lasting advantage over more sheltered, cockier coworkers she no doubt encountered at Microsoft. “I learned a lot about empathy” at Aldus, she would later tell the UK’s Telegraph.

It was around this time that Larson-Green finally learned to program, teaching herself coding during breaks from her day job. Later, she earned a master’s degree in software engineering from Seattle University and upgraded her Aldus gig to become a development lead.

Roughly five years later, Larson-Green found herself in the potentially embarrassing situation of giving a frank assessment of the weaknesses and strengths of software code compilers made by Microsoft, along with those made by Microsoft rival Borland, to a room that turned out to be dotted with Microsoft staffers. But the Microsofties were impressed, and soon roped Larson-Green into a gig helping to oversee the development of Microsoft’s Visual C++ – just the sort of software development tool she had critiqued.

Larson-Green was finally inside the borg, where she found she had a penchant for developing the more humane side of computing, the user interfaces that bridge low-level computer code to actual people trying to complete real-world tasks. After Visual C++, Larson-Green became program manager for Microsoft’s website builder FrontPage and then oversaw user interface design for Office XP and Office 2003.

One of her brightest moments came with the release of Office 2007, for which she oversaw an innovative, context-sensitive user interface known as “the ribbon.” Though initially controversial with some hard-core Office users, the ribbon won wider acceptance and acclaim as an elegant way to expose the growing and often bewildering set of features available within Office. Larson-Green won Microsoft’s “outstanding technical leadership” award for championing the ribbon.

Larson-Green also won recognition for leading the planning around Windows 7, the successor to Microsoft’s poorly received Vista operating system. Where Vista was derided for being late, confusing, and painfully slow, Windows 7 shipped quickly and ran fast too, setting new sales records and winning plaudits in the tech press.

It was Windows 7’s brilliant but bizarrely bifurcated successor Windows 8 that ultimately thrust Larson-Green into the top leadership ranks. Overseen by Sinofsky, Windows 8 proved to be a poor seller, even though it has finally given Microsoft a truly innovative, even beautiful OS across tablets, phones, and PCs. Longtime Windows users were baffled by the new “Metro” interface and retreated into Windows 8’s old-school desktop mode, complaining that, even in classic mode, it wasn’t enough like Windows 7.

In retrospect, Sinofsky should have taken a page from longtime protégé Larson-Green, who, as Microsoft once put it, “decided not to compromise the integrity of Office 2007 with the safety net of a ‘classic mode.’” Although it was Sinofsky who pushed Larson-Green toward her ribbon project in the first place – “I didn’t want to do it,” she once said – it was she who largely assumed his duties once Sinofsky was pushed out this past fall.

It’s hard not to wonder whether Larson-Green will end up replacing a controversial boss once again, if and when Ballmer leaves the company. The longtime Microsoft sales executive has been rightly criticized for allowing once-catatonic rival Apple to surpass Microsoft in driving the growth of personal computing, first through music players and now via smartphones and tablets.

And it’s interesting that when asked about replacing Ballmer at Wired's business conference this past May (see video below), Larson-Green was uncharacteristically blunt. “I wouldn’t rule it out, but I’m not in a hurry,” Larson Green said. “Give me a year and ask me again.”

We definitely will.

Windows VP Julie Larson-Green: Starting Over with Windows from WIRED on FORA.tv