u need to tweak power options in control panel.. turn off monitor,hard disk,suspend etc...
if u have a ups (like APC) which provides a software that shuts down u r system automatically when the UPS battery is low. use that..
I need a UPS to turn off PC when its in low battery.Also I want to power off the UPS output when the PC is turned off so that my modem will be powered off.
Last month my modem downloaded 2GB when my PC was shut down