The EC considers that Microsoft is dominant in the supply of PC operating systems, with a global market share of over 90%. In 2008, the EC started an investigation into the tying of Microsoft’s web browser Internet Explorer to the Windows PC operating system. In the beginning of 2009, the EC issued a statement of objections in which it argued that by tying Internet Explorer to Windows, Microsoft provided its web browser with an unfair advantage over competitors. Rather than risking a hefty fine, Microsoft promised to enable PC manufacturers and end-users to choose between Internet Explorer and competing browsers. PC manufacturers will be free to pre-install any browser of their choice and set it as the default browser. Microsoft will also distribute a “ballot screen” software update to users of Windows PC systems in order to give users the opportunity to choose between twelve different browsers. The EC has launched a public consultation with regard to these proposals.

Microsoft is also expected to publish a public undertaking to disclose interoperability information that would make third party products compatible with Microsoft products. This undertaking will address the concerns raised by the EC in a separate investigation. The undertaking will include warranties offered by Microsoft to third parties that can be privately enforced.