update not supported by system, how can I fix it?
I downloaded this update and installed, it said it is not supported by my system! I am running mountain lion on my 2012 macbook air, what happened?
MacBook Air, OS X Mountain Lion
Go back to the MAS and into the Updates tab. The necessary firmware update should be available to you. Install the firmware update and then go to Sys Prefs > Energy Saver and the setting will be there under the Power Adapter tab.