How to Lock Your PC
Consider locking your computer, rather than logging out. You can lock your computer if you need to go do something else but don’t want to shut everything down, like when you log out. To lock your computer:
Press the Win+L key combination on the computer keyboard (Win is the Windows key, shown in this figure).Windows key features the Windows logo.
Click the padlock button in the lower-right corner of the Start button menu (see this figure).Clicking the padlock icon locks your PC.
As soon as you press Win+L or click the padlock, the initial login screen appears; no one can access the computer at that point unless they have an account and know the account's password. The computer is locked.
Locking the computer is a good, secure thing to do when you need to step away from your computer in an unsecured environment, such as any public place.