I'm having a difficult time solving this problem. I just purchase a seagate 2tb hdd for storage, when I installed it, it is not seen in both bios or disk manager. I installed it on an external drive and it works. I tried other sata port, I have 6 on my motherboard currently have three 1.5tb seagate and 1 western digital, my sytem is window xp pro sp3. What can be the problem? I did notice when I connect the 2tb the computer loads up windows really slow, but when I disconnect it xp loads up fast. Not sure if this will help?