If you get a notebook model like the HPDV1000 or some more expensive media notebooks like the Toshiba Qosmio you don't boot the operating system at all to watch a DVD or play a CD. Thus, the operating system and hard drive are not on.
You can only do this with the instant on software that comes with these machines that allows you to treat the DVD/CD player essentially as a consumer device with instant on separate from the notebook operating system and hard drive.
This obviously saves battery life using these functions and time as well as you don't have to boot the notebook every time you are on the train and want to listen to the DVD or CD.
This special software is likely not compatible with regular notebooks unless it is programmed into the hardware and system bios, etc.
So, in your case you can lower the LCD brightness and take out any USB peripherals plugged in (external mouse, etc) to save batteries but the hard drive is going to be on if your DVD/CD player requires the operating system to be on to access it.
I own a sony vaio A240 (love it). I was just wondering what are the best ways to conserve battery while watching a dvd? i have the screen brightness and all of that configured, as well as the power settings...but is there anything else? like a 3rd party program that can monitor/turn off unnecessary processes when only watching a dvd? i know there are some laptops that have a switch that turns everything off except the dvd "stuff," but i didn't go with one of those brand/model notebook (I think it was a type of AMD product..Powernow?). nevertheless, any help would be great. also, does speedswitchxp really help or just become another program to uninstall?
appreciate the time.

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