 After bundling the Internet Explorer web browser into its Windows operating system in the late 1990s (without requiring a separate purchase) and acquiring a dominant share in the web browser market, the antitrust case "United States v. Microsoft" was brought against the company.In a series of rulings by judge Thomas Penfield Jackson, the company was found to have violated its earlier consent decree and abused its monopoly in the desktop operating systems market.The "findings of fact" during the antitrust case established that Microsoft has a monopoly in the PC desktop operating systems market