So what i can tell from reading this is one of the cables to the hard drive is either disconnected or your having other issues with the hard drive. Im a little confused though as you said you where able to load up the site. What operating system are you using to do so? Are you able to boot off an external drive? if so, Open Disk Utility and check to see if the system recognizes your HD. If not. Disassemble the iMac and check the cables going from the drive to the motherboard. I like to check these iMacs with the LCD on and the aluminum housing off before i reassemble just to be 100% sure.