A security option for locking a workstation so that only the user who locked it or an administrator can unlock it by pressing Ctrl+Alt+Delete and entering the valid password. If you plan to leave a computer running Microsoft Windows NT or Windows 2000 temporarily and you want to prevent unauthorized access to its console but want to avoid shutting down the system, press Ctrl+Alt+Delete.
Then, in the Security dialog box, click the Lock Workstation button on Windows NT, or click the Lock Computer button on Windows 2000.
Network administrators should encourage all users in the enterprise to use Lock Workstation because an unlocked workstation is vulnerable to tampering and can be used to steal or destroy valuable company information. It is easier to lock a workstation than to log off because it takes less time.
Locking a workstation also allows the user to continue running applications in the background. Note that you can lock only computers running Windows NT and Windows 2000; this feature is not supported by Windows 95 and Windows 98.