So... i finally finished upgrading my iMac Aluminium HDD from 320GB to 750GB. The problem is... The original HDD from iMac (Western Digital Caviar 320GB SATA) cannot be detected anywhere! i tried to use an external case and an "USB to SATA adapter cable" then connect it to my iMac using USB port. Nothing... no external HDD detected on my Leopard. So i tried another way. i plug it inside a Windows CPU, using internal SATA data cable. Wanting to detect it and then format it, so i can use it. But still, nothing detected. Even the BIOS menu from my CPU can't detect this HDD... Anyone can give any suggestion about this problem? Because i'm pretty sure, the HDD itself is in good condition (not broken). Thanks!