Government trust-busters suing Microsoft are learning what friends of Bill Gates already know: He relishes a tough game - be it water-skiing, bridge or a federal lawsuit - and he really, really likes to win.

Over the years, America's richest man has been mythologized as everything from boy genius to techno-visionary to corporate predator. But friends and foes agree it's his stubborn competitiveness that best explains Gates' showdown with the federal government."Bill approaches life in a very passionate way," said Scott Oki, a former Microsoft executive. "In water-skiing, it's `Who can make the neatest turns? Who can get through a slalom course the fastest?' Whether it's playing card games or Scrabble or whatever board game, Bill enjoys doing it in part because it's a competitive thing. He can apply his brainpower to coming out on top."

That determination propelled him into computer programming at age 13. It drove him on to Harvard, until he dropped out to run Microsoft, which he founded in 1975 with friend Paul Allen. It helped him lead Microsoft to dominate the world of operating systems, which run a personal computer's basic functions. It made him a billionaire at age 31.

And now it has landed him, at 42, in a high-stakes antitrust battle with the federal government, the results of which could change the way both personal computers and Microsoft operate.

The U.S. Justice Department contends Microsoft is unfairly stifling competition in the Internet browser market by bundling its own browser with Windows, the operating system used in nine out of 10 PCs.

Gates counters that the government is trying to squash the innovation upon which Microsoft has based its success. After nearly two weeks of negotiations with government attorneys, Gates broke off the talks Saturday, saying the government was seeking too many concessions.

It could take years for the legal system to digest the federal lawsuit, filed Monday along with a suit by 20 state attorneys general. But the battle for public opinion is raging now, as the sides try to sell Gates as a corporate bully inflamed by lust for profit and power or a visionary trying to create a better world through technology.

Patty Stonesifer chooses the latter. She is a former Microsoft executive who heads the Gates Library Foundation, through which Gates and his wife, Melinda, are funneling $200 million of their own money to provide Internet access to every public library in America.

"He doesn't do things halfway," Stonesifer said. "He wants to do it at scale. He wants to solve the problem."

Gates himself favors the "vision thing." At a news conference Monday at Microsoft headquarters, he summoned up images of a man and his company beleaguered by meddlesome government regulators.

"Twenty-three years ago, Paul Allen and I started Microsoft on the principle that technology could dramatically improve people's lives," he said.

"How ironic that in the United States, where freedom and innovation are core values, these regulators are trying to punish an American company that has worked hard and successfully to deliver on these values."

Critics say Gates' past successes may give him a false confidence to challenge the government as if it were yet another competitor.

"He's had a hyper-aggressive, take-no-prisoners way of conducting business," said Jesse Berst, editorial director of AnchorDesk, an online news service for the technology industry.