Bork's argument was that it costs money to develop a browser, and Netscape had the right to pass these development costs on to consumers, but Netscape was prevented from doing so by Microsoft's predatory pricing policy of giving away its browser for free at below the cost of developing it.

The act of giving away a browser, according to Bork, harms competition by preventing Netscape and others from commercially developing browsers.

I found it incredible that a person who called himself a conservative and pretented to oppose government regulation would make these arguments. "Predatory pricing" to give away software? Are Red Hat and Mandrake predatory for giving away their products on their servers? How about Larry Wall? He gave away Perl when Microsoft charged for Visual Basic. Is Larry Wall predatory?

I found Bork to be a fatuous idiot. He definitely claimed that it was illegal for Microsoft to give away IE, and that this act of "predatory pricing" harmed Netscape, requiring yet more government intervention advocated by the supposedly "conservative" Robert Bork.

I found Microsoft's arguments on this matter contra Bork to be completely convincing. You can find their response to Bork here. It says:

Perhaps the most remarkable policy pirouette by the 1998 Bork is his assertion that Microsoft deserves to be condemned because it has engaged in predatory price-cutting by giving Internet Explorer away for free. However, as the 1978 Bork would have understood, in light of the circumstances, "giving away" web browsing software is rational and procompetitive. Indeed, the 1978 Bork wrote, "predatory price-cutting is most unlikely to exist and . . . attempts to outlaw it are likely to harm consumers more than would abandoning the effort."