LIKE A PICTURE of Nick Wilson on the front page, Janet Reno's mug shot doesn't inspire much confidence in the news these days. But she looked highly responsible Tuesday pictured next to this headline: "Microsoft cashing in, Reno says / $1 million-a-day fine sought for software giant." It's amazing what a little backbone can do to improve one's posture.

The attorney general says Microsoft isn't playing fair in the computer-software game. Which is an accusation of some importance because Microsoft already owns most of the marbles.

"We won't tolerate any coercion by dominant companies in any way that distorts competition," Janet Reno said. That was also the burden of the formal complaint she filed against Microsoft, Bill Gates' 500-pound gorilla of the computer-software industry. Mr. Gates doesn't monkey around when it comes to making money. According to a report in Vanity Fair on the world's most influential people, he could be the first trillionaire--well before he's 50.

If you're one of the millions of Americans already hooked on Microsoft's computer-operating system called Windows 95, you know what's going on. If not, here's a shorthand version: Microsoft has been accused of violating an agreement with the Justice Department by tying the use of Windows 95 to the use of its browser. Browser? That's what computer experts like your kids use to navigate the Internet. Internet? That's the electronic universe.

Since the introduction of Windows 95 in, yes, 1995, Microsoft has required the makers of personal computers to install the company's Internet browser--called Internet Explorer--on all computers. If the makers of PCs don't include Microsoft's browser, they can't include Windows 95.

Think of it this way: Say a company like General Electric required all makers of lamps to include GE light bulbs--as if telling the consumer that only GE bulbs will work. That's what Microsoft has been doing. Or rather, that's what the Justice Department has accused Microsoft of trying to do. The Justice Department even provides documentary evidence: It seems to show that Microsoft demanded that a computer maker called Compaq feature Internet Explorer--or else lose the license for Windows 95.

Janet Reno's anti-trust division at Justice isn't having any of this. The attorney general has finally acted like an attorney general and advocate of the people. You know, the way Winston Bryant regularly does in Arkansas. A tangential thank-you note: When it comes to watching out for the people, General Bryant has even been known to sue the state. Just the other day, he filed suit against the director of the state's Department of Finance and Administration for a dubious hiring. It's about time somebody in state government did something clear and definite about Grabfest '97, instead of just talking a good game. BACK TO Janet Reno, we all know the attorney general can talk. See her performance before any number of congressional committees. But can she act with conviction and show some foresight? Now she's done both. She not only wants Microsoft to stop bundling the use of Windows with its browser, she also wants Microsoft to tell computer manufacturers and consumers that it has stopped the practice. And she wants a federal judge to order Microsoft fined $1 million a day as long as it insists on the Windows-browser tie-in.

The application of antitrust laws to cyberspace seems as uncertain, undefined, and unexplored as cyberspace itself. We're all still learning about the computer-software market--and most of us are playing catch-up to Bill Gates and Steve Jobs. The U.S. government now has entered the race, and about time.

Surely the country experienced this same kind of feeling-along process back in the days when a few entrepreneurial barons owned most of the railroads. Or John D. Rockefeller was oil, all of it. Or when Ford dominated auto makers and the market. Look what fair competition has done for the price of the automobile. Oops. That may not be the best example. Look what fair competition has done for the quality and variety of automobiles. That's better.

If the Great American Idea and Ideal is to spur technological innovation through aggressive, open competition, then somebody has to look out for the public. Why not the Justice Department? Its latest move certainly beats its keystone-kop performance where those White House tapes were concerned. And the result could be exhilarating: Who knows what marvels Microsoft and Bill Gates can come up with in the face of some real competition?