Once in a while, Cortana will display small snippets of information, suggestions, thoughts, or greetings (which are commonly referred to as "Taskbar Tidbits") in the Search box of Windows 10Taskbar tidbits are meant to improve user experience with the intelligent personal assistant, but if you find these messages distracting, you can turn them off in Cortana's settings.

How To Hide Cortana's Taskbar Tidbits

Open Cortana and click on Menu > Notebook > Settings:

Scroll to the Taskbar tidbits section and toggle the button that reads Let Cortana pipe up from time to time with thoughts and greetings in the Search box to Off:

Photo: 123rom