LUXEMBOURG: A European Union court has thrown out Microsoft's appeal on a 2004 anti-trust ruling that ordered the software titan to share information with rivals and to sell a version of its Windows operating system without Media Player.
A record €497 million ($689m; £345m) fine for monopoly abuse was also upheld.
Microsoft now has two months in which to decide whether to lodge a further appeal to the higher authority of the European Court of Justice.
The company's general counsel, Brad Smith, said the ruling would be carefully studied, adding: "If there are additional steps that we need to take in order to comply with it we will take them."
The Court of First Instance's decision was welcomed by the European Committee for Interoperable Systems. Maurits Dolmans, a lawyer for the group, said: "It's a very good day, for it signals that there will be fair competition for the sector."
A crumb of comfort to Microsoft was the court's reversal of the regulators' decision to appoint a monitoring trustee to oversee the company's compliance with the ruling.
It held that the EC had exceeded its powers in ordering Microsoft to pay all the costs of the trustee.
Data sourced from BBC Online; additional content by WARC staff