mt hdd lost all my info

resently i had a problem with my pc had to start with windows disk started with a windows disk without any service pack so i only recognised 120g and my storage hdd is 200g when i rebooted my pc my storage disk had lost all it info and folders is there anyway to recover my folders and info i lost holyday pic music and movies i cant find the cds and some off the music was from itunes so i cant redownload them without paying again can anyone help me please