No internet connection

Hello,
My computer had no memory when I got it. I bought it from my aunt. Well, she told me to let here friend wipe the computer out and reinstall windows via cd rom (I think thats how its done) well now i have the computer back and it will not connect to the internet via wireless or lan. Now i called comcast thinking it was them and they told me i was missing my local area connections. Now I have a computer and i dont know what to do with it can some please help me out i dont know where to go to get that in the computer! Its a Dell inspirion 1150.
Thanks for all your help
Mary Escobar