Generating a Power Efficiency Diagnostics Report

Windows, for several versions now, has tried to work closely with whatever hardware it is installed upon to manage power use. (In fact, there are several different WindowsTips that explain how to change power settings.) When you are working on a laptop, power use becomes much more important than it may be on a desktop computer. If you want to know how to best configure Windows and your laptop to co-exist peacefully and make the best use of the computer's battery life, you might be interested in generating a power efficiency report.

Normally this report is "hidden," meaning that the tool that creates the report is not available from any of the controls in the Windows environment. Instead, you need to run it from the command prompt, as an administrator. To get to the proper command prompt in Windows 7, follow these steps:

1. Click the Start button to display the Start menu.
2. Type cmd, but don't press Enter. You should see a single command shown on the screen, for cmd.exe.
3. Right-click on cmd.exe and choose Run as Administrator from the resulting Context menu. This opens up a command line prompt window.

If you are using Windows 8, move the mouse pointer all the way to the bottom-left corner of the screen and then right-click. In the resulting Context menu, choose the Command Prompt (Admin) option. If you are using Windows 10, right-click on the Windows button. In the resulting Context menu, choose the Windows PowerShell (Admin) option.

In the command prompt window, enter the following:

powercfg –energy –output c:report.html

Depending on your version of Windows, you may need to insert either a back slash (\) or a forward slash (/) between "c:" and "report" in the above command prompt entry.

The powercfg program starts and informs you that it is doing some diagnostics for 60 seconds. The program actually takes a bit longer than a minute to run, as it needs to do some analysis on the results of the diagnostics. In the command line you can change the report name and location; the example shown places the report (report.html) in the root directory of the C: drive, but you could specify a different location, if desired.

When completed, you can close the command prompt window and navigate to wherever the report is located. Double-click on it, and it will open in your browser. It contains quite a bit of information about your system and its power usage. You can use the information in guiding you on how to configure Windows to give the best power performance on your system.

 This tip (7097) applies to Windows 7, 8, and 10.