Windows 7 includes the Power Configuration utility (Powercfg.exe) for managing power options from the command line. You can view a list of parameters for this utility by typing powercfg /? at a command prompt. The parameters you’ll work with most often include:
–a Lists the available sleep states on the computer and the reasons why a particular sleep state is not supported.
–d [guid] Deletes the power plan specified by the globally unique identifier (GUID).
–devicequery all_devices_verbose Lists detailed power support information for all devices on the computer. Be sure to redirect the output to a file because this list is very long and detailed.
–energy Checks the system for common configuration, device, and battery problems and then generates an HTML report in the current working directory.
–h Toggles the hibernate feature on or off.
–l Lists the power plans configured on a computer by name and GUID.
–q [guid] Lists the contents of the power plan specified by the GUID. If you don’t provide a GUID, the contents of the active power plan are listed.
–requests Displays all power requests made by device drivers. If there are pending requests for the display, these requests would prevent the computer from automatically powering off the displays. If there are pending requests for any device including the display, these requests would prevent the computer from automatically entering a low-power sleep state.
–s [guid] Makes the power plan specified by the GUID the active power plan.
–x [setting] [value] Sets the specified value for the specified setting in the active power plan.