Windows 7 and Server 2008 include a hidden power efficiency diagnostic report that can help make your computer more energy efficient. The report is generated through the powercfg utility and monitors your computer for 60 seconds. Power settings, hardware and what you computer is doing is all monitored to identify power waste. Once completed, the report will show errors, warnings and general information about the power efficiency capabilities of your hardware and what is preventing it from operating efficiently.
Generating the report requires access to an administrative level Command Prompt. Click on the Start Button, type in cmd, hold down CTRL and SHIFT and then hit Enter. That will start an administrative level command prompt.
Next, type in powercfg /energy and hit enter.
After the report is generated the file is placed in c:\windows\system32\. Before you can open the report with a browser, copy the file to your desktop first. Both Firefox and Internet Explorer seem to have issues opening files from the System32 folder.