On November 12, 2013. Microsoft CEO Steve Ballmer have a reach Windows Phone 8.1 can release in winter 2013 (December 2013), was the final update for Windows Phone, but was re-released in April 2014, they have many running for the features codename is <nowiki>"</nowiki>Windows Phone Blue<nowiki>"</nowiki> was released on April 15, 2014, on April 16, 2014, Microsoft reach Cortana launched to Windows Phone Blue, has been the name for Microsoft, after release on April 2, 2014, from Microsoft website, on April 19, 2014, Microsoft notification the security update was released for Windows Phone Blue, launched for Defender phones device.