Windows 7 is designed to reduce your display brightness after several minutes of inactivity on your laptop computer. The display can use more power than any other part of a laptop computer—even more than a hard disk and CPU, hence this feature is very useful to conserve battery life. Some laptops have a dedicated button or dial to change the display brightness.
Many laptop users rely on the manufacturer supplied software to monitor the laptop battery status and condition while few are the users that perform power efficiency reports which can help them fix power related issues. The Powercfg command in Windows 7 enables users to control the power settings and it has a slew of command options such as, listing all power schemes of the current configuration, displaying the contents of a specified power scheme, changing a setting in the current power scheme and many more. To list all options, type powercfg /? from an elevated command prompt.