Microsoft Corp. is under the European Commission's spotlight again and could face more fines if it does not meet a November 23 deadline for turning in secret Windows protocols as required by the March 2004 anti-trust decision.

The world's largest software maker has failed to provide the complete and accurate interface documentation, the EC said in a statement on Wednesday. In July, the commission fined Microsoft $357 million (€280.5 million) for failing to reveal the software protocol which allows competitors to produce rival products.

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 European Union's executive body said.

Microsoft's first deadline after the March 2004 decision was set for July the same year. The EC says the software giant has committed to and missed a number of deadlines for delivering the complete and accurate specifications; the last deadline was on the 19th July 2006.