—May 1998: Justice Department and 20 state attorneys general sue Microsoft, charging it illegally thwarted competition to protect and extend its monopoly on software.
—October 1998: Justice Department sues Microsoft for allegedly violating a 1994 consent decree by forcing computer makers to sell its Internet browser as a condition of selling its popular Windows software.
—April 3, 2000: U.S. District Judge Thomas Penfield Jackson finds that Microsoft violated the Sherman Antitrust Act, “maintained its monopoly power by anticompetitive means” and attempted to monopolize the Web browser market. The judge also rules that Microsoft unlawfully tied its Web browser to Windows.
—June 7, 2000: Jackson orders the breakup of Microsoft into two companies.
—Sept. 26, 2000: Supreme Court refuses to hear Microsoft’s appeal of Jackson’s decision, sending the case to a federal appeals court in the District of Columbia.
—Sept. 6, 2001: Bush administration Justice Department announces that it will no longer seek a breakup of Microsoft.
—Oct. 31, 2001: Microsoft, Justice Department reach tentative deal to settle antitrust case.
—Jan. 23, 2002: AOL Time Warner Inc. sues Microsoft, seeking damages for Microsoft’s actions against the Netscape browser, which AOL had acquired.
—Mar. 8, 2002: Sun Microsystems Inc. files antitrust suit against Microsoft, alleging extensive anticompetitive practices.
—August 2002: Microsoft unveils several business and product changes to comply with Justice Department settlement, including giving users the ability to hide Microsoft programs like its Web browser and only see competing products.
—Nov. 1, 2002: U.S. District Judge Colleen Kollar-Kotelly approves most provisions of settlement.
—May 29, 2003: AOL Time Warner settles with Microsoft for $750 million.
—June 16, 2003: West Virginia quits the antitrust battle, leaving Massachusetts as the lone state challenger to the Justice Department settlement.
—Dec. 18, 2003: RealNetworks Inc. sues Microsoft, accusing it of illegally monopolizing the growing field of digital music and video.
—March 24, 2004: European Commission fines Microsoft a record $613 million for antitrust violations and orders it to divulge some trade secrets to competitors and produce a version of Windows without a bundled program that plays music and video files. The sanction is later suspended while a judge hears Microsoft’s appeal for immediate relief.
—April 2: Sun settles for $1.6 billion from Microsoft.
—June 30: U.S. appeals court unanimously approves settlement with Justice Department, rejecting objections from Massachusetts that the sanctions are inadequate.
—Nov. 8: Novell Inc., which had raised antitrust claims in Europe, settles them for $536 million.
—Dec. 22: An EU court rejects Microsoft’s appeal of the March order that the software giant disclose trade secrets and produce a version of Windows without the Media Player program. The decision effectively thwarts Microsoft’s attempt to delay implementation.