SAN FRANCISCO, CA – APRIL 02: Joe Belfiore, corporate vice president and manager for Windows Phone, holds Windows phones during the keynote address at the 2014 Microsoft Build developer conference on April 2, 2014 in San Francisco, California. The 2014 Microsoft Build developer conference runs through April 4. Justin Sullivan/Getty Images/AFP== FOR NEWSPAPERS, INTERNET, TELCOS & TELEVISION USE ONLY ==