Computer Lock Up 

Computer Lock Up is an efficient solution for many companies: it helps people to protect their computers while they are away. It can also be useful for schools, net cafes, and practically anywhere else where computers are used publicly.

The program works by forcing a black screen on your desktop, which cannot be removed until a password set by the user is provided. The program cannot be defeated, as it will disable all your keyboard keys while running in protection mode, so the users cannot just terminate the process of the program or minimize it. Plus you can choose to lock the computer on Windows startup, and it will be launched even before the Windows login dialog is displayed.

The program is more useful than the built-in Windows lock functionality: it can prevent the CD/DVD drive's door from being opened, even if the physical door button is pressed. Another unique feature is the ability to automatically lock your computer after a certain amount of minutes of inactivity. If you want to confuse the non-privileged users, you can hide the password prompt box, and use your special hot key for displaying it. The program can also work totally invisibly, hiding its tray icon, and making you use keyboard shortcuts to lock the computer or show the tray icon again.