What did you mean by: "try to change those settings" about Lenovo Energy Management?
I love Lenovo's Energy Management and it's up-to-date, so it's impossible to uninstall it :)
The problem isn't from the Energy Management, it is from the more power options! If i change brightness (for ex: for Balanced, and from Energy Management, it is placed Balanced, it won't change (the brightness slider down doesn't affect the brightness too!) So I'm guessing its a Windows 7 problem?
While when I press "FN" and button up (brightness up) button down (brightness down) the laptop changes the brightness and shows Lenovo's box as it fills and empties when increasing or decreasing the brightness....
I also formatted my laptop after installing Windows 8 a month ago (cause I didn't like it; and Lenovo lacked many drivers), and reinstalled my Lenovo's original Windows by the recovery disks I created via OneKeyRecovery when I got my laptop. The brightness was working before the format!!