Justice Dept. Expands Probe of Microsoft : Computers: Action stems from reports that certain Web browsers won’t work under Windows 95. Company says the problems are unintentional.

Federal regulators are again turning up the heat on PC software giant Microsoft Corp.

Late last month, the Justice Department issued a new round of civil subpoenas to Microsoft’s competitors--this time the companies that design software for browsing the Internet.

Government lawyers, who have been investigating alleged unfair business practices by Microsoft for about five years, have grown increasingly concerned over reports that a number of Internet browsers do not work under Windows 95, the Microsoft operating system introduced in August.

Microsoft executives have acknowledged “compatibility problems” between Windows 95 and some software, including Netscape Communications Corp.’s popular Internet browser. But they insist the problems are unintentional.

“It’s not that you can’t use a Netscape browser, it’s just that it’s not as transparent as it could be,” Microsoft senior vice president Steve Ballmer said in a recent interview with the Los Angeles Times. “We strive for compatibility. We would not break someone’s browser by design.”

Among the companies contacted by the Justice Department during this round of information gathering are Netscape and online service providers such as H&R; Block’s CompuServe and Prodigy, a co-venture of IBM Corp. and Sears, Roebuck & Co. The latest phase of the investigation was first reported Monday by the Wall Street Journal.

Windows 95 users can access the Internet easily using the Microsoft Network, an online service whose access software is included as part of the operating system. Competitors in that business have complained that by including an online service with Windows 95, Microsoft has an unfair advantage.

In the weeks before the launch of Windows 95, the Justice Department issued a round of civil subpoenas to America Online, CompuServe and Prodigy. But the department opted not to delay the release of Windows 95 by ordering the Redmond, Wash.-based company to package the online service and the operating system separately. It did, however, promise continued vigilance.

Since then, any danger that Microsoft would dominate the online industry has faded somewhat as everyone involved in that industry--including Microsoft--scrambles to figure out how to cope with the rise in popularity of the Internet. But since the release of Windows 95, competitors and consumers have complained that Microsoft has made it difficult to use a non-Microsoft browser.

Prodigy spokesman Brian Ek said the company was contacted by Justice Department employees about two weeks ago.

“Our browser works with Windows 95, but a number of the major browsers are disabled under Windows 95,” Ek said. “These browsers existed before Windows 95, so if there is an onus on anyone, it should be on Microsoft to do better work.”

CompuServe spokesman William Giles said his company incurred significant time and expense to alter its Internet access software so it would work with Windows 95.

On a technical level, the dispute revolves around a piece of software called the Winsock, which enables Windows software to understand Internet protocols. The Microsoft browser replaces any previously installed Winsock with its own--which the company says is not an underhanded trick but merely a way to build a standard Winsock that all browsers can use once they are configured to do so.

Whether the latest Justice Department subpoenas will lead anywhere is unclear. The initial investigation of Microsoft by the Federal Trade Commission and then the Justice Department ended in a settlement last year that many regarded as a slap on the wrist. But last spring the department filed a lawsuit that stopped Microsoft’s acquisition of personal finance software maker Intuit Inc.

“I think the Justice Department is serious about this investigation, but what does serious mean in the context of [Assistant Atty. Gen. for Antitrust] Anne Bingaman and the government?” said one person close to the inquiry who asked not to be identified. “Are they dedicating resources to it? Yes. Are they thinking about it hard? Yes.

“Are they going to do anything? Who knows?”