thanks for your reply... actually there is one sata dvdrw drive and another 80gb IDE hdd, both are working fine but only the WD sata 320g HDD id not getting detected ... even in bios, i have tried it on different systems, even tried it through a sata to usb converter on my laptop... but all in vain. i mean its hardly been 3 months since i bought it. theres no clickin sound etc. runs fine when powered..so i dont think its a physical damage. what might me the problem... ??