Microsoft today lost its courtroom appeal against the biggest single fine ever imposed by the European Commission.
The computer software giant hoped to overturn a £343 million penalty for abusing its "dominant position" by effectively keeping rival software firms out of the market.
But Europe's second highest court today threw out the appeal, saying it was "beyond dispute" that Microsoft obliged customers to buy its Windows operating system along with the company's Media Player software.
The Commission imposed the fine because it said Microsoft was using its powerful position in the computer software market to keep rivals out.
As well as the fine, Brussels insisted that Microsoft offer Windows without support software - and offer rival firms the necessary communications codes for their own software products to operate with Windows.
Today, the European Court of First Instance said the fact that Microsoft "bundled" Windows with its own software and did not charge any extra costs was "irrelevant".
The judges said tying the product together and not providing the necessary technical information to rivals to enter the same market was an abuse of Microsoft's dominant position.
The company was studying the complex judgment today, and is almost certain to launch another appeal, this time to the European Court of Justice, the final arbiter in anti-trust cases.
The European Commission welcomed the ruling against Microsoft - and the company's rivals described it as a great day for European businesses and consumers.
The European Committee for Interoperable Systems - a coalition of computer software companies - said the judges had finally opened the door to competition in the computer software industry in a verdict against monopoly pricing.
"This is a great day for European businesses and consumers," said Thomas Vinje, ECIS spokesman.
He praised the Commission for its "persistence" in pursuing the case against Microsoft.
"The time has now come for Microsoft to obey the law. The provision of interoperability information is common software industry practice. Microsoft knows full well what is required and how to provide it and now just needs to do it."
Mr Vinje added: "This decision means that no company, especially one with a super-dominant position, is above the law."Reuse content