I know its late. but dont know wether you have figured it out or not,
Just adding my idea, though i am not a pro.
You need to have SQL 2012 management studio.
If you can open your SQL configuration manager, you see the instance name on which you want to enable ALWAYS ON option.
Go to the properties window, you can see a tab mentioning always on.
It need to be turned on, If you dont have any specific Fixes, it will suggest you to install.
If you have all the set up, you should be good to enable it.
DID this help you???