It introduced a Browser Choice Screen pop-up in March 2010 as part of a settlement following an earlier EU competition investigation. But the US company dropped the feature in a Windows 7 update in February 2011. Microsoft said the omission had been the result of a "technical error".
But competition commissioner Joaquin Almunia said the action was unprecedented, adding he wanted to deter any company from the "temptation" of reneging on such a promise.
In theory the watchdog could have fined the firm 10% of its global annual revenue, which would have totalled $7.4bn based on its 2012 report.
"We take full responsibility for the technical error that caused this problem and have apologised for it," a spokesman for Microsoft said following the announcement. 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."
One lawyer said the ruling was also intended to send out a message to others.
Source: BBC News
