The easiest way to lock your computer when you leave your desk is to press Win+L, provided your user account is password protected. You can also automatically lock your computer when you move away from it by taking advantage of Bluetooth’s ability to detect Bluetooth devices around the vicinity of the computer. That’s a very geeky way to do it. But if you really want to show off, you should use Quark.
Quark is a simple security tool for Windows that protects your computer from unauthorized access by locking the screen and denying any user interaction until the correct password is entered. And it does it in style. The whole screen is covered with Matrix styled rows of green scrolling characters with a password box in the foreground. Accompanying the visual effects there are high-tech, robotic sound effects that can be heard during locking, typing keys and unlocking.
To activate Quark you have to double click on QLoad.exe and set your password. Then double click on Quark.exe to lock the screen. When the screen is locked you can’t access any application of the computer. Not even Ctrl+Alt+Del works.
However the biggest annoyance of the program is that you have to set your password each time you lock the system. There is no way to set it permanently. If you execute Quark.exe without setting the password through QLoad.exe, the screen can be exited by pressing Enter.
[via Shell Extension City]