Older ATI drivers and cards had the options for Direct3D and Open GL, today the new Catalyst Control center merges both into one category called 3D. So it here is here you want to adjust your 3D settings.
Expand the 3D settings section and select the "Anti-Aliasing" sub-category on the ATI or if you have an Nvidia, go into the "Manage 3D settings" option (Make sure you are in Advanced View check under the View menu).
Sample ATI Screen
Next find the following options which fall under the 3D settings categories and adjust as follows:
For an ATI card check off the box 'Use application settings' box, so that the level of Antialiasing can be set within particular games for example and won't conflict with your Control Center settings.
For an Nvidia card select the 'Force Antialiasing Off' for all games regardless of their in-game settings
- Adaptive Anti-Aliasing
For an ATI card uncheck "Enable Adaptive Anti-Aliasing" if you have choppy frames and slow performance. If this is checked it will increase the quality of the appearance at the expense of processing power which could make it slower.
Similarly for an Nvidia card you would lower the rate to 2X or 4X or turn it off and turn off the transparency option.
- Anisotropic Filtering
For an ATI card uncheck the "High Quality AF" box, and leave checked the "Use application settings".
For Nvidia, adjust the settings down for performance similar to as mentioned above.