1990: Federal Trade Commission (FTC) secretly investigates possible collusion between Microsoft and IBM.

1993: US Justice Department takes over Microsoft investigation.

1994: Microsoft and Justice Department sign agreement that Microsoft cannot require computer-makers that license its Windows operating system to license other software products as well.

In October, Microsoft announces the proposed $1.5 billion acquisition of Intuit, maker of Quicken personal finance software.

1995: Microsoft drops Intuit acquisition in the face of a separate Justice Department lawsuit.

In August, US District Judge Thomas Penfield Jackson approves the Microsoft/Justice Department agreement.

1996: US Government investigates possible violation of the agreement by Microsoft.

1997: Justice Department asks Judge Jackson to fine Microsoft $1 million a day for allegedly violating the agreement by bundling together Internet Explorer with Windows 95.

In December, Judge Jackson issues a preliminary injunction against Microsoft. Microsoft appeals Jackson's decision and offers computer-makers a version of Windows 95 without Internet Explorer.

1998: On May 12th, the appeals court rules that Jackson's injunction against Microsoft should not apply to Windows 98, allowing Microsoft to proceed with the launch of its new product.

Later that month, the Justice Department, 20 US states and the District of Columbia file major new antitrust cases alleging that Microsoft abused its market power to thwart competition.

In October, the Microsoft antitrust trial begins before Judge Jackson.

In December, the state of South Carolina withdraws from the case, leaving 19 states supporting the federal government.

1999: February 16th: The first phase of the Microsoft trial goes into recess after hearing 12 witnesses from each side and videotaped testimony, including that of Microsoft chairman Bill Gates.

June 24th: Microsoft trial testimony ends.

November 5th: Judge Jackson finds that Microsoft has monopoly power in the market for personal computer operating systems, and that it used this to harm consumers, computer-makers and others. There are reports that he is about to split Microsoft in two.

2000:

May 10th: Microsoft asks Judge Jackson to reject the proposal to divide up the company and proposes lesser remedies.

June 5th: Government files slightly revised break-up plan with the court, incorporating only minor changes proposed by Microsoft. June 6th: Microsoft makes its final filing in the case a day earlier than expected, clearing the way for a final ruling.