I'm helping a friend. She has a late 2009 iMac 21.5 inch MC413LL/A, Model A1311. Appears to be the base model. She went to start it up and it gives the grey start screen but stays there with the rotating whatever it is on screen. She hears clicking. I tried walking her through single-user mode but she couldn't get in there either. She does have an OS X install DVD that came with it. I am thinking she has a dead hard disk. Any ideas, or does she need to bring it to Best Buy (where she bought it) and have it repaired? I ran out of ideas, but my tech knowledge on Macs is considerably less than Wintel boxes.