Symbian S60 or Windows molile or ???

It seem that you don't really understand the meaning of "smart"phone. Don't you notice that the menu of your cellphone is some kind of similar with your computer's. Both of them have "start", including software like Windows Media Player and so on. Don't tell me you don't even know the operating system on PC. If you do, then you would surely understand the your cellphone has got some kind of similar stuff on it. All your software installed on it is on the base of "operating system?" For your cellphone, you could consider the operating system of your cellphone is cellphone edition of windows operating system. For Nokia, it's S60 and S40 series. And every smart phone has its own operating system including Apple, Plam and black berry.