If you plan on leaving your desk for any length of time, always lock your computer. You are responsible for keeping company data safe and preventing anyone else from using your system without a password. Keep others from possibly copying or deleting your files, installing programs and malware, or sending emails that indicate they were sent by you. After-hours personnel; cleaning crew, part timers, and maintenance should never have access to your computer unless they have their own login. Whenever you leave your desk you should lock your computer. PC users- press the Window key +L, or press Ctrl+Alt+Del and lock.