Putting Cortana off the lock screen

You can put Cortana on the lock screen for comfort, but doing so could put your Windows 10 device at risk if you leave it unattended in a public place – a passerby could use the digital assistant to peek at your messages or something similar.

However, removing Cortana from the lock screen is simple. Click the Cortana/search box, then the Settings cog, and look for the option to "Use Cortana even when my device is locked." There's a slider just beneath this that needs to be turned off, and that's all there is to it.