The European Commission determined back in July that Microsoft failed to follow through with a 2009 commitment to provide Windows users with a browser choice ballot box in Windows 7. Microsoft admitted fault, citing a technical error in Service Pack 1 as the reason that 28 million PCs failed to see the agreed-upon browser choice screen.

The commitment stems from a European Union case that found Microsoft had abused their dominance in the market by not providing users with a broader selection of web browsers. And by broader, we mean only Internet Explorer.

At the time, a Microsoft spokesperson said they deeply regretted that the Service Pack error occurred and they would take immediate steps to remedy the situation. This included hiring a third party to conduct a formal investigation into how the incident occurred. Microsoft agreed to submit a full report to the European Commission at the conclusion of the investigation.

The commission has since filed a formal complaint against Microsoft that could cost the company a lot of money. If found guilty, Microsoft could be forced to hand over 10 percent of their annual turnover. Based on fiscal year 2012 revenue, Redmond could be looking at a fine in the range of $7.3 billion.

A statement issued by Microsoft says they have discussed the matter with the commission and will be changing some aspects of the way the Browser Choice Screen works in Windows 8. These changes will be implemented when the operating system launches later this week.

Microsoft will have a month to respond to the formal complaint before the commission makes a final ruling.