Window 7: Power Efficiency Diagnostics Report

Windows comes with a command line utility called POWERCFG.EXE for managing your system's power configuration. This utility has an option called -ENERGY that can analyze your system for common energy-efficiency and battery life problems. When it finishes running, it will generate an HTML report file in the current path.

Note: This command should be used when the computer is idle and with no open programs or documents.

•  From the Start menu, in the search field type CMD.EXE, then press the Ctrl+Shift+Enter keys all at the same time.  This should start up the command console in administrator mode.
• At the command line, type powercfg -energy and press the Enter key.
  

 It will take about 60 seconds to the report to run. When its finished it will display a path to a HTML report it generated.