When Microsoft Corp. releases the first public beta version of Windows NT 5.0 next week -- its new network operating system -- you'll hear the distinctive sound of a bullet being loaded into the chamber. A year later, the gun will fire. Here's the question: Will Novell and Netscape be in the line of fire? Or will they have out maneuvered Microsoft and lived to fight another day? Microsoft Corp. will release the NT 5.0 beta next week at the Microsoft Professional Developers Conference, a company spokeswoman said. But the company would not provide an exact release date. The conference, held in San Diego, runs Monday through Friday. Several developers said they expect the release Tuesday. The final version is scheduled for release next summer. The long testing time will allow corporate customers to test the software for bugs. For those people not intimately involved with the computer industry, the hoopla over NT seems a far distant second in importance behind what's happening with Microsoft's Windows 98, the next version of the ubiquitous operating system. But to Microsoft, NT is no less important, because the company that controls corporate networks controls the industry. "NT is core to Microsoft's strategy," said Harry Fenik, vice president at Zona Research Inc. "This is the next step in penetrating the enterprise and staking their claim to ownership of the enterprise server environment." Earlier versions of NT have already claimed victims. Last week, Artisoft, the maker of networking software for small- and medium-sized businesses, pushed out its CEO and all but raised the white flag, declaring the company has unsuccessfully competed against NT and Windows. And many of the travails of networking giant Novell, which just a few years ago owned 80 percent of the networking software market, have come from NT. Now Novell's share has slipped to 50 percent, while Microsoft has garnered 25 percent and is rising, according to market researcher International Data Corp. "Novell's future is completely up for grabs— these guys have got to find a silver bullet," said analyst Fenik. "They fell victim to the rise of NT." NT 5.0 significantly improves upon earlier versions of the product, and raises the bar for competitors, analysts said. New features in 5.0 include Active Directory, a directory of users on the network; improved security features; IntelliMirroring, a feature that allows users to use their own PC interface no matter what computer they log on to; improved storage features; and "Zero Administration," automated software installation and maintenance that reduces corporate information system headaches. But in the nine months or so between the beta and final release of 5.0, Novell and Netscape will have time to bolster their own network offerings. Novell wants to marry its knowledge of corporate networks with the wild new world of the Internet. And Netscape, while not offering a network operating system of its own, hope to create Internet-based networking solutions that build on its expertise in network servers, e-mail and browsers. If they can find the silver bullet, Microsoft will have competition for years to come. If not, the silver bullet will be aimed their way.