Quoting a couple of people described as being "familiar with the matter," Reuters says the fine might be "significant."
Microsoft has been in hot water with the European Commission for some time. Last fall, regulators said the company reneged on a 2009 promise to give Windows consumers. The latest bit of upset has to do with Microsoft's failure to include a "browser choice" screen for European users in the latest version of Windows 7 last year. At the time, Microsoft said it was an oversight, blaming a technical error which missed the update in February 2011 in store shelf copies of the operating system. All told, roughly 28 million European users may have been affected.
"While we believed when we filed our most recent compliance report in December 2011 that we were distributing the [browser ballot] software to all relevant PCs as required, we learned recently that we've missed serving the [browser ballot] software to the roughly 28 million PCs running Windows 7 SP1," the company said at the time.
We've contacted Microsoft for comment and will update this post when we have more information.