I had this ATI problem - Here is how I fixed it.
On the task bar or from the start menu , start the "Catalyst Control Center"
On the menu on the right hand side, select "Gaming" and "3d Application Settings"
On the right hand settings panel - these are your default settings:
For:
Anti-Aliasing - set mode = "User application settings"
Morphological filtering "unchecked"
Filter = "standard"
Anisotropic Filtering: set "Use application settings" = checked
Tessellation - set "Use application settings" = checked
Catalyst A.I. - Texture = "high quality"
"Enable Surface Format Optimization" = unchecked
Vertical refresh: Anti aliasing = performance
Opengl - doesn't matter
Click "apply"