Computer security has been a hot topic for a few years, and a good security practice is to lock your computer when you walk away from it. One of the quickest ways to lock your computer's screen is press the WinKey+L key (if your computer keyboard doesn't have the WinKey, then you can press the Ctrl-Alt-Del keys, then Enter). When you lock your computer's screen, you will be required to enter your log-on password to access your computer again (or have an administrator password).