Troubleshoot Power Management Settings in Windows 7

Windows Vista includes a command line tool, Powercfg.Exe, that you can use to configure power management settings. Windows 7 introduces a new switch, /energy, to provide a comprehensive report of those settings. It also offers diagnostics that can indicate which applications or devices might be causing power management issues (such as a USB driver not entering suspend) and what power management settings you can configure differently for better results. At an elevated command prompt, simply enter:
POWERCFG –ENERGY –OUTPUT <path\filename>
The tool will observe your computer for 60 seconds, and then create a file called ENERGY-REPORT.HTML in the path you specified. Simply double-click on this file to see what’s going on.