Judgment in United States v. Microsoft Corp.

On 03/04/2000, U.S. District Judge Thomas Penfield Jackson issued his Conclusions of Law in the case United States v. Microsoft Corp., ruling that Microsoft had violated the Sherman Antitrust Act. The decision followed earlier findings of fact in November 1999 and addressed Microsoft’s conduct in the market for personal computer operating systems and web browsers. Judge Jackson concluded that Microsoft held monopoly power in Intel-compatible PC operating systems and had taken actions to maintain that position. The ruling stated that Microsoft engaged in exclusionary and anticompetitive practices to protect its operating system dominance. Judge Jackson also found that Microsoft attempted to monopolize the web browser market through actions directed at competitors such as Netscape Navigator. In addition, the court determined that Microsoft illegally tied its Internet Explorer browser to the Windows operating system, making it difficult for computer manufacturers and users to remove or replace the browser. The April 2000 Conclusions of Law set the stage for subsequent remedies proceedings, including a later order proposing that Microsoft be split into separate companies. The decision became one of the most significant antitrust rulings involving a technology company in the United States.