A European Union court will decide next Monday on Microsoft's challenge to a 2004 landmark European Commission decision imposing fines and sanctions on the software giant over antitrust violations.

Here are some of the key events in Microsoft's 17 years of legal battles with regulators and private companies from the European Union, the United States, South Korea and Hungary:

-- June 1990: U.S. agencies open investigation into Microsoft.

-- July 15, 1994: European Commission, U.S. Justice Department settle with Microsoft on ending anti-competitive practices.

-- October 20, 1997: U.S. charges 1994 settlement was violated.

-- November 24, 1997: The Commission, the EU's top antitrust regulator, settles charges over Microsoft licensing to a developer of the Unix operating system, Santa Cruz Operation.

-- April 3, 2000: U.S. judge rules Microsoft used monopoly power to block competition, later orders Microsoft be broken up.

-- August 3, 2000: Commission sends so-called statement of objections after Sun Microsystems complaint on licensing.

-- June 28, 2001: U.S. Court of Appeals rules unanimously Microsoft used Windows monopoly to block competition, but halts break-up.

-- August 30, 2001: Commission sends second statement of objections, charging Microsoft acted to block competition from rivals making audiovisual software and low-end servers.

-- May 29, 2003: Microsoft pays AOL-Time Warner $750 million to settle lawsuit on Netscape browser technology.

-- August 6, 2003: European Commission, in an unusual move, sends Microsoft third statement of objections.

-- March 24, 2004: Commission imposes record 497.2 million euro fine, orders Microsoft to make Windows available without Windows Media Player and give rival server software firms more information so their products can run well with Windows.

-- April 2, 2004: Microsoft settles Sun Microsystems case for $2 billion; Sun withdraws from EU case. Microsoft pays InterTrust Technologies $440 million to settle separate case.

-- June 8, 2004: Microsoft appeals Commission ruling to EU Court of First Instance (CFI) in Luxembourg.

-- November 9, 2004: Microsoft pays $536 million to Novell Inc., $20 million to the Computer & Communications Industry Association. The two withdraw EU complaints.

-- July 8, 2005: CFI judge removed as head of Microsoft case, which is transferred to special panel of 13 CFI judges.

-- October 5, 2005: Commission chooses technical software specialist Neil Barrett -- one of three nominations by Microsoft -- to help evaluate the company's compliance with antitrust remedies.

-- October 11, 2005: Microsoft settles antitrust case with RealNetworks for $761 million. RealNetworks ends third-party involvement in support of Commission in Microsoft appeal at CFI.

-- December 7, 2005: South Korean Fair Trade Commission fines Microsoft $32 million for blocking competition, orders it to separate instant messaging system from Windows.

-- December 22, 2005: European Commission threatens Microsoft with daily fines of up to 2 million euros retroactive to December 15, 2005 for what the EU executive says was a failure to provide documentation on interoperability.

-- March 3, 2006: Microsoft requests U.S. courts intervene to gain access to EU documents. All three courts involved deny request.

-- April 24-28, 2006: Hearing on underlying case before CFI.

-- July 12, 2006: EU Commission fines Microsoft 280.5 million euros over alleged failure to provide interoperability information.

-- October 13, 2006: Microsoft agrees to alter new Windows Vista to satisfy some EU concerns.

-- March 1, 2007: Commission alleges Microsoft plans to overcharge for interoperability information.

-- July 26, 2007: Hungary raids Microsoft Hungarian subsidiary on suspicion of abusing market power.

-- September 17, 2007: Ruling by Court of First Instance set.

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