Have a look at ...

How to Remove Cortana from the Windows 10 Taskbar
http://www.howtogeek.com/220955/how-to-remove-cortana-from-the-windows-10-taskbar/

'On Windows 10, Microsoft has integrated Cortana right into the taskbar, which is fine since Google has no problem slapping its search feature on Android’s home screen. Unlike Android, however, Windows 10 easily allows you to change how much space Cortana takes up on the taskbar. By default, it appears as a search bar that says “Ask me anything”.'

Or see ...

How to disable Cortana from the task bar in Windows 10
http://www.windowscentral.com/how-disable-cortana-task-bar-windows-10

If neither help, please let us know.

Best of luck!