This is, of course, only one of the ways to maximize your battery life—your best bet is to adjust your screen brightness and get rid of crapware applications that abuse the CPU.
Using the Troubleshooter
You can click through a whole bunch of Control Panel links to get to the troubleshooter, but it’s a whole lot easier to just type improve power into the search box, and then click on the resulting item in the list.
The wizard will apply the changes by default, but you can click the Advanced link and uncheck the option for applying automatically if you’d like.
Once you’ve run the wizard, it will check for any potential problems in your settings—if you’ve adjusted your power plans in a way that isn’t a good idea, for instance. You can also use the View detailed information link…
This will show you a huge list of items, and you can see that the wizard didn’t find any problems with those items.
Even if your PC doesn’t have the problems listed, it’s actually rather interesting to look through—for instance, did you realize that a screen saver wastes battery power?