The European Union fined Microsoft $732 million for breaking the terms of its 2009 antitrust settlement last year by silently removing the Browser Ballot Choice interface from Windows 7. Microsoft, which says it did so inadvertently, is the first company that’s ever broken a voluntary agreement with EU regulators and the fine was aimed in part in sending a message to other would-be scofflaws.

The fine follows an October 2012 statement of objections, in which the EU formally charged Microsoft with violating its agreement.

“Legally binding commitments reached in antitrust decisions play a very important role in our enforcement policy because they allow for rapid solutions to competition problems,” EU Competition Chief Joaquin Almunia said of the fine. “Of course, such decisions require strict compliance. A failure to comply is a very serious infringement that must be sanctioned accordingly.”

Microsoft spent several years challenging every other antitrust-related ruling against it, but is unlike to do so in this case. Instead, the firm is focused on pushing EU regulators to enact similarly harsh sanctions against competitors such as Google.

This week’s fine dates back to part of the 2009 EU antitrust settlement, in which Microsoft agreed to offer a Browser Ballot Choice interface in versions of Windows sold in EU countries. This screen allows consumers to choose between Microsoft’s Internet Explorer, which is bundled with Windows, and competing web browsers.

In 2011, however, the Browser Ballot Choice interface was removed from Windows 7 as part of the Service Pack 1 update. Microsoft says this was a mistake tied to a technical error and the company apologized as soon as EU regulators caught on in mid-2012. But with the interface removed from Windows for an amazingly lengthy 18 month period, the EU understandably questioned how Microsoft did not notice the omission.

“We take full responsibility for the technical error that caused this problem and have apologized for it,” a Microsoft statement notes.  “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.”

Microsoft has now been fined a total of almost $3 billion by EU regulators.