If you’re using Windows 10 Professional or Enterprise, the easiest way to disable Cortana is by using the Local Group Policy Editor.

Launch the group policy editor by pressing Windows + R, typing gpedit.msc into the box, and pressing Enter:

Navigate to Computer Configuration > Administrative Templates > Windows Components > Search.

Locate the Allow Cortana setting in the right pane and double-click it:

Set the Allow Cortana option to Disabled and then click OK:

You can now close the group policy editor. You’ll have to sign out and sign back in – or restart your PC – for this change to take effect.

See original article here:
https://www.howtogeek.com/265027/how-to-disable-cortana-in-windows-10/