Occasionally, you also need to protect add a layer for your running computer even if you just need to step away from it for a few minutes, especially in a public place. For this, you can consider locking your computer. Once your computer is locked, it will prompt for the password to log into your Windows.
To lock your computer, the easiest way is to use the Win+L key combination. Press the Win+L key combination on the computer keyboard. The Windows logon screen will soon appear. Anyone who wants to access to the computer needs to type the right password for the user account.
In Windows 7, you can also press CTRL+ALT+DEL to lock your computer. A password will also be required in order to get back to the desktop. Besides, you can do this job by clicking the padlock button in the lower-right corner of the Start button menu.
Additionally, Windows comes with the ability to enable screen saver password. Windows would automatically lock itself as soon as the screen saver comes up. On resume, you will be asked for the password before you can enter.