Had a spare bay in my laptop, and put a SATA 160 gig HD in purely for backup. Became apparent that I needed more space, so bought a Seagate 500 gig internal HD as a replacement. First thing I noticed is that the original 160 drive had SATA power, and SATA data connections but NOT the 4 pin connection. The new one did have the 4 pin connection. Only difference. My problem is that when I plug the new drive in, the computer OS doensn't recognize it. Put the old drive back it, no problem.
Running WIN 7 Ultimate, on a Toshiba laptop. can give specs if necessary, but should be plug and play, yeah?