After adding a sata dvd writer, whic became the 3rd sata drive, the second ( Seagate barracuda 500gb)goes missing. It shows up in bios and 'device manager' , but not in 'disk management' or 'my computer. System: win. xp pro. home, gigabyte motherboard, amd dual core processors. The missing drive is partitioned: 'new voume': F, G, and H. I would appreciate your help.