The lock screen is the screen you see when you lock your PC (or when it locks automatically after you haven’t been using it for a while). The lock screen will also show at startup, and when you are signed out and idle for one minute. You will need to dismiss the lock screen to be able to see the sign in screen and sign in to Windows. Users can dismiss the lock screen using touch, the keyboard, or by dragging it up with the mouse.
Starting with Windows 10 build 18932, a new hidden experimental feature is available to enable adding a search box on the lock screen allowing users to search the web with Bing directly on the lock screen.
If enabled, the search box will only be on the lock screen when users lock the computer (Win+L). The search box will not be available on the lock screen at startup.
When users type in the search box, it will show them Bing web search results. If a user clicks/taps on a link in the search results, it will only open in Microsoft Edge after they sign in.
This tutorial will show you how to enable or disable a search box on the lock screen to search the web with Bing for all users in Windows 10.