I have used Smart Utility demo and it shows failing for the Hard Drive. it shows about 8 sectors are bad. Also I don't have any OS discs but I plan to get some later on this year or next. I have run or at least tried erasing or repairing but now I can't do anything as it shows that it cannot be unmounted. It does show that 698.64 in about this mac. Any ideas? do I have a bad HD? should I return it?