Hardrive not reading

Hello,
i got my new computer. i have an ipod and im trying to download my music from lime wire on to my ipod. for some reason when i turn my computer on and i plug in my ipod to the hard drive its not showing that the computer is reading it. so i cant have the option to downoad my music. the computer is not showing me that my ipod is plugg into to it. what should i do.