Microsoft has submitted the latest batch of technical information about its Windows operating system to the European Commission antitrust department, meeting the last in a string of deadlines imposed by the regulator over the past two years.

Microsoft called the submission "an important milestone". Final edits and technical review of information that the company submitted previously to the regulator, in July, have now also been completed, it added.

"Now the submission from Microsoft is worth testing," said Jonathan Todd, the Commission's spokesman. "Licencees will be invited to Microsoft's headquarters in Redmond to look at it."

Last week, the Commission's antitrust chief, Neelie Kroes, expressed growing impatience with Microsoft when she imposed yesterday’s deadline.

She described the dossier submitted in July as incomplete and warned Microsoft that it faced daily fines of €3m (£1.6m), back-dated to the end of July, if it didn't hand over all the technical information about Windows that it was ordered to reveal in a March 2004 antitrust ruling.

Microsoft claimed yesterday that it had met its deadline. "The Trustee and Microsoft have now completed the technical review and edits to the more than 100 documents, totalling 8,500 pages, that we submitted in July of this year, in accordance with the deadline established by the Commission," the company said.

The submission of technical documentation in July, and the revision process since then, was described as "an unprecedented undertaking involving over 300 engineers and technical writers at Microsoft".