Can someone please give me the specifics on a 3.5 internal hard drive for my iMac G5 (17") running Leopard. My old HD was getting very full so I decided to replace it. I bought a Seagate 3.5 1TB at Staples ("good for PC or Mac"), brought it home, ripped into my iMac, removed the old HD and opened the new Seagate. Turns out it was for tower computers only. Took it back to Staples, where I learned that iMac HDs are Apple specific. Called the local Apple store. Was told that they didn't carry HDs in stock but I could schedule an appointment with the Genius Bar and someone there could determine what I need. I know what I need -- a new HD --I just don't know where to get one or order it online because descriptions from online suppliers are not generous with the knowledge about what works with what. Never thought it would be so frustrating just to buy a replacement drive.