The Windows 7 service pack 1, rolled out between mid-2011 and mid-2012, failed to offer consumers a choice of browser, leading to the EU investigation that resulted in today's fine.
Microsoft said the failure was the result of a technical error and that procedures have since been tightened.
In what was seen as an acknowledgement of the severity of the mistake, the board cut the bonus of chief executive Steve Ballmer last year, according to company's annual reports.
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Big companies will have to show that their supply chains do not use the slave labour or exploit people, David Cameron has announced.
Disneyland Paris is reportedly facing a pricing probe amid claims it charges British tourists more than its French customers.
Overworked GPs are becoming so tired they could be putting patient's safety at risk, the head of British general practitioners has warned.