EU regulators fined Microsoft 561 million euros on Wednesday for failing to give users the choice of web browsers other than its own Internet Explorer.
The fine, which represents 1 percent of the Internet giant’s global revenues for 2009, was levied because the firm breached a 2009 anti-trust settlement.
Microsoft admitted it had failed to provide browser choice software on some 28 million computers.
“Although Microsoft did make the choice screen available in March 2010, as agreed, the choice screen was not rolled out as required following the launch of Windows 7 Service Pack I in May 2011,” said Joaquin Alumnia, the EU’s competition commissioner.
The US company has had a long history of clashes with EU competition regulators, paying nearly 2.24 billion euros in fines over the past decade.
The European Commission has already told Microsoft to change how it presents Internet Explorer in its new Windows 8 package or face another anti-trust battles.