Microsoft is improving up the power management capabilities in the upcoming Windows 7 operating system with features designed to reduce energy consumption, also to improve battery life and give IT administrators and Microsoft partners tools with which to better troubleshoot and handle power management issues. Windows 7 will come with improved Trigger Start Services. Systems services tend to start automatically and run in the background, waiting for an event to happen to be put into use. Prior to Vista, the systems services could be turned on or off. With Vista, that was improved to having the systems be delayed. With Windows 7 and the Trigger Start Services feature, the system service will start only if an event starts it.
More info: eWeek