Microsoft has handed over more documentation in an attempt to persuade the European Commission that it has complied with the 2004 antitrust ruling.
The EC announced on Monday that it has begun studying the information from Microsoft, which relates to server interoperability protocols.
Earlier this month, the EC fined Microsoft 1.5m euros (£1m) per day, backdated to last December — a total of 280m euros — for failing to supply information to help its rivals create server software that was fully interoperable with Windows.
The EC had given Microsoft until Monday, 31 July, to make itself compliant with the 2004 ruling, warning that the daily fine would rise to 3m euros if it failed.
An EC spokeswoman declined to say how long it would take to analyse the technical information provided by Microsoft, as the Commission's competitions services team, led by UK computer expert Neil Barrett, will have to review it in detail first.
"The fine won't necessarily go up. It depends on what Microsoft has submitted," said the EC spokeswoman.
According to Microsoft, it submitted its documentation to the EC on 18 July. Codenamed Paddington, it is the seventh and final piece of technical documentation that Microsoft was due to submit.
"This last instalment represented 2,600 documents [pages], and further demonstrates our ongoing commitment to reaching full compliance with the Commission's Decision of March 2004," said a Microsoft spokesperson.
"We are working with the Trustee [Neil Barrett] to ensure that all of this documentation meets his requirements, and to respond promptly and fully to any further requests for information. We look forward to working with the Trustee and the Commission to complete our compliance effort," Microsoft added.