Cortana is the intelligent personal assistant and knowledge navigator for Windows Phone 8.1. CNBC's Jon Fortt speaks with Stefan Weitz, Microsoft senior director - Bing, about the Cortana search ... more 
Cortana is the intelligent personal assistant and knowledge navigator for Windows Phone 8.1. CNBC's Jon Fortt speaks with Stefan Weitz, Microsoft senior director - Bing, about the Cortana search experience and its new devices. less 
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Thu, Apr 10, 2014 12:54 PM EDT