How to Disable Cortana Windows 10 Anniversary Edition
On a system running Windows 10 Home, you need to make a manual edit to the registry. Find the keyHKLM\Software\Policies\Microsoft\Windows\Windows Search
(you might need to create this key if it doesn't exist),
Right click on Windows folder and new Key and name it Windows Search
and then create the DWORD 32 value AllowCortana and set it to 0.