The European Commission (EC) has threatened Microsoft with daily fines of €3 million (£1.6m) if it doesn't provide interoperability information about its Windows operating system by 23 November.

This is the latest in a string of deadlines imposed over the past two years in an effort to get Microsoft to license technical documentation for Windows that would allow rivals to develop server software programs to interoperate with PCs running Windows.

"The Commission expects the remaining omissions and deficiencies in the technical documentation to be remedied by 23 November so that by the end of November the entire set of technical documentation will be available for potential licensees to review," the Commission said.

The order to reveal the documentation was part of the Commission's March 2004 antitrust ruling against Microsoft, under which it also find Microsoft €497m (£264m). In July this year, the Commission fined Microsoft a further €281m (£149m) for failing to submit the information.

Competition Commissioner Neelie Kroes repeated her frustrations in an interview published Wednesday in The Guardian newspaper. "I am not impressed if someone says 90% of the information is already there when we need 100%. It's a jigsaw and some parts are missing.

“In my opinion, this information should have been here a couple of months ago," she said.

Microsoft issued a statement Wednesday, but avoided commenting on the imposition of a new deadline. "Microsoft is committed to full compliance with the Commission's March 2004 decision and we are working closely with the Commission and the Monitoring Trustee towards that goal," it said.

Microsoft initially claimed that it didn't understand what information the Commission wanted. The 2004 ruling ordered the firm to make available enough information about Windows to allow makers of rival server software programs to design their products to work as seamlessly with Windows as Microsoft's own server operating system. After a hearing earlier this year, Microsoft said it finally understood what the Commission was after, and submitted what it said was the final instalment of information on July 19.

Since then the Commission has been examining the documentation together with the monitoring trustee, Neil Barrett, who was picked by Microsoft to oversee its compliance with the 2004 ruling.

"As of today, the Commission has not received the complete documentation regarding all relevant protocols that is required to comply with its March 2004 Decision," the Commission said Wednesday.

Commission competition spokesman Jonathan Todd said in a news conference that near compliance isn't good enough. "Until we have the whole set of documents, what they have provided is worth nothing," he said.
Todd wouldn't say whether failure to meet next week's deadline will automatically trigger new fines.

"The Commission will decide in due course whether or not the technical documentation is in full compliance with the requirements of the March 2004 Decision taking into account comments from the potential licensees and advice from the Trustee on whether the technical documentation is operational," the Commission said in its statement.

Todd said the dispute about compliance with the 2004 antitrust ruling has no bearing on the launch of Microsoft's latest operating system, Windows Vista, to computer manufacturers this month.