Many wonder why the world's wealthiest person would relinquish control of arguably one of the world's most influential companies to assume the somewhat ambiguous tasks of a "chief software architect."

But Gates looked like he was struggling to contain his delight Thursday, when he said he would hand over his chief executive reins to Microsoft President Steve Ballmer, so he could take on a more visionary role in software development.

Gates said he wants to return to his roots in programming, an early passion, which consumed him as a teenager, and which he later dropped out of Harvard University to pursue full time.

``I'm returning to what I love most -- focusing on technologies for the future,'' Gates said Thursday at a surprise news conference at the company's Redmond, Wash., headquarters.

Asked if he would now be perched in front of his computer writing software code, Gates quipped: "I might be threatening to write code. That's something that I haven't been able to do in three or four years."

Gates May Have Become Bored

But some analysts believe Gates, 44, tired of his corporate duties, especially with the world's largest software company now embroiled in a lengthy Justice Department antitrust suit that could drag on for years.

Last year, Microsoft was found to have used monopoly power to crush its competition. The company is currently braced for a ruling on a remedy, which could be as extreme as a court-imposed breakup of the software giant.

In videotaped testimony at the government's antitrust trial last year, Gates repeatedly claimed he did not remember key details in his company's development of an Internet browser and its negotiations with rival Netscape Communications Corp. Government lawyers called his performance under oath ``bizarre'' and ``simply not credible.''

Such criticism may have spurred the software titan to take a leap in a new direction. But others say it's simply a personal choice.

"Clearly Gates is bored," said Michael Gartenberg, a Microsoft watcher and vice president of the Gartner Group, a technology research firm. "He loves innovation, and he loves to play with the technology. This will let him do that."

Said Jeff Raikes, Microsoft group vice president for sales and support and a close friend to Gates: "This is what Bill really wants to do. He's been chomping at the bit to take this on."

That's not to say that Gates, who had been CEO for Microsoft's entire 25-year history, was never happy in the top spot. The meteoric rise of Microsoft, as well as Gates' personal wealth, is proof of Gates' business acumen — and, critics say, his ruthlessness.

The onetime high-school computer nerd, who has since redefined what truly wealthy means, is worth about $80 billion due to his holdings in Microsoft.

Ballmer Seen as Perfect Fit

Meanwhile, Ballmer, who has been at Gates' side for nearly 20 years, is a perfect fit to assume the title of CEO. Ballmer, 43, is seen as rather loud and blustery — he didn't bother with a microphone at Thursday's news conference — but his business credentials are impressive. As Microsoft's long-time vice president of sales, Ballmer helped make Windows a household name through the 1990s.

His new role, insiders said, is nothing more than an extension of his role as president, a post he assumed in July 1998. At the time of that promotion, he ran full bore through the crowd at a company meeting at Seattle's Kingdome, the theme from the "Superman" movie booming through the speakers.

"What people miss is that despite everything, Ballmer gets the job done," Gartenberg said. "This is a natural evolution of his role."

With Ballmer at the helm, Microsoft will likely become more aggressive as it enters new technology markets with its new Internet strategy. As Ballmer announced Thursday, the company will market new software that can be accessed through any device — from personal computers and handhelds to cell phones and toasters — via the Internet.

Ballmer is the son of Swiss immigrants who grew up in Detroit, where his father worked for Ford Motor Co. He holds a degree in applied math and economics from Harvard, and worked at Procter & Gamble Co. as an assistant product manager. He attended the Stanford Graduate School of Business.

Ballmer's bulldog attitude is what attracted Gates when he first met Ballmer at Harvard University, where both were students. The two have collaborated closely ever since, and Ballmer calls their relationship "totally unique in the business world." Gates made him best man at his wedding to Melinda French.

Their vision is identical when it comes to the company's direction, but now Gates will focus nearly all of his energies on the technology, while Ballmer brings the business end along.

"Steve is a great manager and a great motivator," Raikes said. "I've worked for Steve for 18 years, and I can say that the company's in good hands."

And while Ballmer takes charge of the company, Gates can return to shaping the company's next-generation vision for Windows.

In the end, though, Microsoft's business will not change radically. Gates said software developers will see new tools and new software by this summer, but the average consumer won't see any radical innovations from Microsoft for at least two years. Until then, it'll be business as usual at Microsoft, if there is such a thing.

"Think of this as the next chapter in Bill and Steve's excellent adventure," Gartenberg said.