Justice Department Expands Probe Of Microsoft

The Justice Department is stepping up its anti-trust inquiry into Microsoft’s new on-line service by sending out a new round of civil subpoenas, an industry source said Thursday.

The source, who has met with Justice attorneys, said companies are being asked to provide information about on-line registration of their software. The companies were not identified by the source, who spoke on condition of anonymity.

The Justice Department is trying to estimate how big a share of the market Windows 95 and the Microsoft Network will gain after the Aug. 24 roll out.

The size of Microsoft’s share of the market would be important to support claims that Microsoft may be able to use its dominance in operating system software to get an unfair advantage in new fields, such as on-line services.

Microsoft’s Windows and MS-DOS products are standard operating systems, which control a computer’s basic functions, such as interaction of the keyboard with the screen and printer.

The company’s plan would give everyone who uses Windows 95 easy access to Microsoft Network while other on-line services must rely on other distribution methods, such as advertising or paying PC makers to include their software.

The Justice investigation stepped up this week with a second round of civil subpoenas to companies concerning their on-line registration data, the source said.