My Existing SATA Hard Drive is not detecting

Hello,
I just installed windows vista home premium sp1 on my computer and my existing SEAGATE 500GB is not detecting in Computer or Disk Management. I recently bought a new BIOSTAR motherboard and AMD Phenom X3 /710 2.6GHz processor. I had a non activated copy of vista ultimate until my copy of Windows Vista Home Premium just came in and i installed a fresh copy. My point is visat ultimate detcted my secondary seagate hard drive fine. Windows home premium doesn't detect it in either placed above. I downloaded sea tools and it passes every test but it still does not detect on my computer yet. I'm pretty computer savvy. Please inform me how to get my other hard drive detected. This hard drive is not new i have used it for about a year now.