May 1998: The U.S. Department of Justice, 20 states and the District of Columbia sue Microsoft, accusing the company of illegally engaging in predatory practices to protect its monopoly in personal-computer operating systems.
October 1998: The antitrust trial begins in U.S. District Court for the District of Columbia.
January 2000: Microsoft Chief Executive Bill Gates announces he will become chief software architect and Steve Ballmer will be CEO.
April 2000: U.S. District Judge Thomas Penfield Jackson rules Microsoft unlawfully maintained a monopoly in Windows and unlawfully tied its browser to Windows.
June 2000: Jackson orders a breakup of Microsoft into two companies.
September 2001: Justice says it would no longer seek a breakup of Microsoft.
November 2001: Justice and Microsoft agree on a proposed settlement for the antitrust case.
November 2002: U.S. District Judge Colleen Kollar-Kotelly approves the settlement; Microsoft is ordered to comply with a five-year consent decree.
May 2006: Microsoft and Justice agree to extend the consent decree until November 2009.
January 2008: Kollar-Kotelly grants extension.
April 2009: Parties agree to extend the consent decree to May 12, 2011.
May 2011: Consent decree expires on May 12.