When you asked where to find it I thought you meant the drivers themself, It has since struck me that you may have meant the option in the CCC rather than the driver. if so, and I presume you are using the CCC as opposed to vision or something else, do this..
Open the CCC, under the headings at the right side click 'Gaming' then '3D application settings', on the page that opened there will be a bunch of different options, the order will be ..
Smoothvision HD Anti-aliasing, then under that Smoothvision HD Anisotropic Filtering, then under that is Disable Catalyst A.I with a checkbox and a slider, tick the box, ignore the slider and press apply at the bottom. That'll be it done.
I'm surprised there are versions of the control panel Vision, etc, that don't have the Catalyst A.I options directly, I've never used one that didn't.