Antitrust has been an issue between Microsoft and the federal government for more than 10 years. Here are key points through that history.
June: Microsoft learns the Federal Trade Commission is investigating the development of Windows and OS/2, another operating system.
Feb. 5: FTC deadlocks 2-2 on whether to pursue the case.
Aug. 20: Microsoft learns the Justice Department is assuming jurisdiction over the case.
July 16: Microsoft settles with Justice, signing a consent decree agreeing to alter Windows licensing policies with PC makers.
Jan. 10: Silicon Valley attorney Gary Reback, representing unidentified clients, challenges the settlement, asserting it doesn't curb Microsoft's dominance in operating systems.
Feb. 14: U.S. District Judge Stanley Sporkin rejects the settlement.
June 16: An appeals court overturns Sporkin's ruling; the case is reassigned.
Aug. 21: U.S. District Judge Thomas Penfield Jackson approves the settlement.
August: Silicon Valley companies say they have contacted the Justice Department about Microsoft's unfair practices.
Sept. 20: Microsoft says it has been notified of a new investigation related to Internet access.
Oct. 20: Justice files suit, charging Microsoft with violating the 1994 consent decree by conditioning licensing of Windows 95 on computer makers' including the Internet Explorer browser in their products.
Dec. 11: A Jackson-issued preliminary injunction prohibits Microsoft from forcing computer makers to ship Internet Explorer with each Windows 95 machine.
Dec. 15: Microsoft appeals the preliminary injunction.
Jan. 22: Microsoft agrees to offer working versions of Windows 95 without the browser.
May 12: A three-judge appeals-court panel rules Jackson's injunction does not apply to Windows 98.
May 18: The federal government and 20 states sue Microsoft, accusing the company of predatory practices to protect its monopoly in personal-computer operating systems.
June 23: The appeals court clears the way for Microsoft to package Internet Explorer with Windows 95.
Oct. 19: The trial begins. Government attorneys accuse Microsoft of using its monopoly position to bully, bribe and attempt to collude with others in the industry, while illegally expanding and protecting its Windows franchise.
Oct. 20: Microsoft strikes back, calling the government's case misguided and erroneous.
Feb. 26: The defense rests. Trial begins a three-month break.
June 1: The trial resumes for rebuttal testimony.
June 24: The testimony phase of the trial ends.
Nov. 5: Jackson issues the first of two rulings, that Microsoft is a monopoly.
Nov. 19: Jackson names Chicago Federal Circuit Judge Richard Posner to mediate a settlement.
Jan. 22: Both sides present final arguments to Judge Jackson.
April 1: Settlement talks before Posner collapse.
April 3: Jackson finds Microsoft violated the Sherman Antitrust Act; Microsoft says it will appeal.
April 28: Justice Department and 17 states propose that Microsoft be split into two companies and be subject to a number of business-conduct restrictions.
May 24: Jackson holds a one-day hearing on proposed remedies, cutting off a Microsoft request for more time.
June 7: Jackson orders Microsoft to be split into two companies and imposes conduct restrictions.
Sept. 26: The U.S. Supreme Court rejects an expedited review, leaving it to a D.C. appeals court.
Feb. 26-27: Both sides argue their cases before the appeals court.
June 28: The appeals court, in a stinging rebuke of Jackson, reverses the break-up order, finds the company did illegally attempt to maintain its monopoly on Intel-based PC operating systems but did not illegally attempt to monopolize the market for Web browsers. It remanded the case to U.S. District Court.