Microsoft has lost its appeal to see sanctions against the company suspended until a wider appeal by the EU is heard.
The President of the Court of First Instance, the European Union's second-highest court, has ruled that Microsoft must offer a version of its Windows PC operating system that does not include its Media Player software, and must also publish APIs that will make it easier for rivals to make workgroup server products that work well with Windows.
You can read the lengthy decision on the EU website here.
The software giant failed to prove that carrying out the sanctions imposed by the European Commission would cause "serious and irreparable harm" to the company, the court said.
The decision is a blow to Microsoft, which appealed against the Commission's decision issued in March, when it also fined the company 497 million euros for abusing its operating system monopoly. It means Microsoft will have to comply with the measures pending the outcome of a longer-term challenge to the decision which is expected to take as long as five years.
Microsoft is allowed to appeal CFI President Bo Vesterdorf's decision, but the appeal will be difficult to argue and must be based on concerns regarding matters of law, as opposed to facts in the case. Vesterdorf has effectively pre-empted such an effort by writing a long and detailed judgment.
Microsoft has responded to the decision in a statement where it repeatedly made the same point: "While we had hoped that the Court would suspend some or all of the remedies in the case, we are encouraged that the Court has recognised that Microsoft has a number of powerful arguments that must be considered in the full appeal."
Tellingly though, it did not state it would appeal Vesterdorf's decision.
Scarlet Pruitt in London contributed to this report.