From FSPro Labs:
Lock My PC by FSPro Labs is one-click system locking software that ensures no one but you can access your private data when you leave your computer unattended. Just press the hotkey on your keyboard or double-click the TaskTray icon to lock down your PC. Once that is done, only the person who knows the correct password may access the computer, what others will see is your lock screen. Windows hotkeys and mouse movement are disabled. Lock My PC is fully customizable: from custom lock screen image to security level settings every possible option can be configured to suit your needs.