The Microsoft antitrust trial inched close to a final ruling from U. S. District Judge Thomas Penfield Jackson on Tuesday, as the software vendor fried a brief refuting his contention that the company has a monopoly in PC operating systems. Microsoft also claimed that U. S. government prosecutors have not satisfied the burden of proof for any of their antitrust claims. Microsoft made the arguments in its proposed conclusions of law—a document of more than 100 pages—fried with the court Tuesday stating the company's interpretation of how antitrust law should be applied to Jackson's findings of fact. The software giant said having an extremely popular product—Windows—does not make it a monopolist. In his findings of fact issued November 5, 1999, Jackson said Microsoft 'enjoys a monopoly' in the personal computer market. A month later the government and 19 U. S. states alleged in their proposed conclusions of law that Microsoft engaged in illegal 'monopoly maintenance' to protect and extend Windows' dominance and then tried to monopolize the Internet browser market. Microsoft refuted all those claims in its brief Tuesday, citing numerous cases and court findings over the past 30 years. The company said the case law demonstrates that it did not engage in anticompetitive conduct that contributed significantly to the maintenance of a monopoly. Microsoft also cited the June 1998 Appeals Court ruling that called the union of Windows and Internet Explorer 'a genuine integration' The brief comes one week after reports began circulating that the government is preparing to propose the breakup of Microsoft into two or three parts. It restates many of Microsoft's defenses, claiming that the integration of Web browsing software into Windows benefited millions of consumers and that the software vendor did not prevent users from obtaining Netscape Navigator. Jackson's findings of fact expressly found that 'many—if not most—consumers can be said to benefit from Microsoft's provisions of Web browsing functionality with its Windows operating system at no additional charge,' the document says. The brief further states that the findings of fact did not say that Microsoft acted with a specific intent to obtain monopoly power in the market for Web browsers. 'The Court instead found that Microsoft attempted to increase Internet Explorer's usage share to such a level as would prevent Netscape Navigator… from becoming the 'standard' Web browsing software,' the Microsoft brief said. While the government argues that Microsoft's actions may have made it more difficult for Netscape to use certain channels of distribution, Microsoft's filing cites numerous cases that demonstrate that its actions were within the bounds of competition defined by the law. Microsoft also rejects the government's claim that its licensing agreements illegally prevent computer manufacturers from modifying the first screen that a user sees when Windows launches, saying the license merely restate rights that Microsoft enjoys under federal copyright law. The two sides in the trial, which began in October 1998, can now submit rebuttals to each other's conclusions of law. Oral arguments are scheduled for February 22, and a ruling is expected in the spring. What conclusion did the government and 19 states draw on Microsoft's case?