MICROSOFT’S customers, retailers and competitors will tell the European Commission this week whether they believe the company has done enough to comply with a landmark anti-trust ruling against the software giant last year.

Their opinions will influence the Commission’s own judgment. If the EU executive decides that Microsoft, headed by Bill Gates, is not complying fully with the moves designed to introduce greater competition into the software market, it can impose a daily fine of up to 5 per cent of the company’s worldwide turnover. A spokesman for the Commission said: “We have asked market participants to give us their comments in the next few days. By the end of the first week of March, we should have all the comments and we will make up our mind after that.

“We will reach our decision on the basis of the results of the market testing and the reactions of companies affected, such as retailers and computer manufacturers.”

Last March, the Commission fined Microsoft a record €497 million (£342 million). The fine represented less than 2 per cent of the group’s global revenue, far less than the 10 per cent it could have been ordered to pay. Mario Monti, the then Competition Commissioner, said after the five-year investigation: “Microsoft has abused its virtual monopoly power over the PC desktop in Europe.”

The company was told to offer a version of its Windows operating system without its video and music Media Player software. It also had to make the necessary technical information available to competitors so that their products could operate more effectively with the Windows server.

To satisfy the conditions, the Commission is insisting that Microsoft refrain from any commercial, technological or contractual measures that would make the unbundled items less attractive.

One of the factors it will take into account is the name given to the new system to ensure that this is not designed to deter customers. On these grounds, the Commission is understood to have rejected the suggestion of a “Reduced Media Edition”.

A spokesman for Microsoft said: “We are committed to comply fully with the Commission decision and are working constructively with the Commission towards that goal.”

The company is appealing against the decision before the EU’s Court of First Instance in Luxembourg, and a verdict is expected later this year.

Microsoft also argued that it should not have to introduce the different remedies demanded by the Commission until the judges had ruled on its appeal.

The court rejected that request shortly before Christmas last year.