The Surface’s lock screen is a full-screen, Metro-style experience that appears when you resume your tablet from sleep. locking Surface Screen requires a little learning, but it’s very easy and quick. Here is a quick tutorial on How to Lock Surface Screen.
* Use WinKey + L.
* On the Start screen, tap and hold on user-tile given at the top right-side and select “Lock” from the menu.
* Type Ctrl + Alt + Del key and choose lock menu from the option.