The controller comes enabled. However, the OP may have to change the type of controller that is enabled. I've only had it happen to me once. I was using a foxconn board with a IDE hard drive and SATA opticals. However, the controller in the BIOS was set to IDE only, I had to change it to IDE/SATA combo. The bios setting will be different for each board though, it may not even be a problem.
That's probably what I deserve for using a lower end board like that.