How to Disable Cortana in Windows 10

Sorry, Cortana — not everyone likes you. =)

1. Launch the group policy editor by pressing Windows + R, typing gpedit.msc into the box, and pressing Enter.
2. Navigate to Computer Configuration > Administrative Templates > Windows Components > Search
3. Locate the Allow Cortana setting in the right pane and double-click it.
4. Choose Disable and click OK
5. Reboot

Optionally, without rebooting:

1. Press Windows +R and type gpupdate /force into the box and press Enter
2. Press Windows +R and type taskkill /f /im cortana.exe into the box and press Enter