Already Installed win7 on my old wd hard disk 320gb is now stopped detecting on my new mobo with new processor ( tried on many computers but no detection)...inside disc is neither rotating nor hdd vibrating so i tried different circuit of wd hdd 500gb on my hdd then inside disc was spinning & hdd vibrating either but not detecting tho...so it means my circuit is dead or i simply need to replace another circuit of wd 320gb to my hdd???? what to do?