The European Commission’s Directorate-General for Competition has opened a non-compliance investigation of Microsoft, prompting the company to admit it has “fallen short” of fulfilling its 2009 assurance to allow users of its Windows operating system to easily choose their preferred web browser.  The commitment was part of an agreement that allowed Microsoft to escape a fine and marked the end of a series of long-running antitrust challenges that cost the company more than €1.6 billion in penalties.  The Competition Commissioner Joaquín Almunia says it will fine Microsoft if the allegations are true.