Allanphua, It's just a matter of Resetting the Settings inside the options for that tool. It's just a matter of using the option-box next to the menu item (the little square to the right), then going to the Edit menu and selecting Reset Settings. 1) Just hit f4 (modelling menu hot-key) 2) Go to Create->NURBS Primitives->Sphere[] (option-box) 3) Edit->Reset Settings. Here's a pic.