why isnt my aero available

hello to all i hace a ? about vista home basic and my ? is how to reach and get to aero u see when i go to personalization all i have is basic and standard options i dont have the aero option and i have researched a bit and i see that vista basic says that it doesnt have aero so then why in performance information and tools it says Graphics: Desktop performance for windows aero = a score
THANKS IN ADVANCE
RUBEN