Many people have been asking me lately “I just installed Windows Vista from Windows Xp on my laptop and I notice my battery life has been draining a lot fast then when I had Windows Xp installed on it, What could it be?”. It has nothing to do with how you installed Windows Vista. So no need to reinstall or call Microsoft. The reason the battery life has been draining faster is the new Aero interface. By disabling the Aero feature the battery will last longer.
To disable the Aero theme do the following:
You can do this by right-click on your desktop and select Personalize from the menu. Choose Windows Color and Appearance and then click on open Classic Appearance Properties for more color options. Select a (non Aero) theme and then click apply.