Yeah, I'm pretty sure it's the coherence thing. I had the Win10 developer preview and the final running fine on P10 and Cortana worked fine when full Win10 was open. I upgraded to Parallels 11 two days ago ($40.00 from OWC.com) and now it works in Coherence mode. I don't actually have full Windows open but I can say, "Hey, Cortana," and a small Cortana window opens and will answer questions and open apps--even Mac apps. Kind of cool. Though not sure it's $40.00 worth of cool.