The European Commission has fined Microsoft over its failure to promote rival web browsers, other than its own Internet Explorer.
Despite introducing a browser selection screen to its operating systems in March 2010 as result of a previous EU investigation, the feature was subsequently removed in an update to the firm’s Windows 7 OS in February 2011.
As a result, the EU Commission has fined the firm $731 (£484m) over the failings.
Microsoft has maintained that the removal of the feature was simply a result of a ‘technical error’.
"We take full responsibility for the technical error that caused this problem and have apologised for it," said a Microsoft spokesperson.
"We provided the Commission with a complete and candid assessment of the situation, and we have taken steps to strengthen our software development and other processes to help avoid this mistake – or anything similar – in the future."
However, the EU commission has continued to take action against the firm in order to prevent others firms from similar activity.
Tony Woodgate, a lawyer from Simmons & Simmons, told the BBC: "The European Commission is sending a firm signal in this first case of its type that it will not tolerate failure by a company to comply with the commitments it gave to settle an antitrust infringement procedure."
Microsoft could have potentially faced an even larger fine over the issue, as the EU Commission could have fine the firm up to ten per cent of its global annual revenue, which based on a 2012 earnings report, would have resulted in a figure close to $7.4bn.
Issues over Microsoft’s web browser offering date back to 2007, when Norwegian firm Opera complained that Microsoft had stifled browser competition on PCs by strictly offering Internet Explorer with its operating systems.
Initially arguing that the move benefitted users rather than hindered them, Microsoft introduced the browser selection pop-up in order to avoid a fine from the EU Commission.
Throughout the period following the removal of the selection screen, Microsoft believes it had still adhered to the agreement – a statement disputed by the Commission, which found the firm had ultimately abused its position.