Laptop Alarm is a free anti-theft software for Windows portable notebooks. When any one of the following condition occurs, a very loud, almost deafening sound alarm is rung to notify the owner of a possible theft:

-When someone unplugs the A/C adapter
-When someone unplugs the USB mouse.
-When someone shuts down or logs off the laptop

This makes sense when a stranger is not aware that such a utility might be running on the laptop. The usage is pretty simple: whenever you want to secure the laptop, start the application and lock the computer.

Download Laptop Alarm for Windows XP and Vista here