Sounds like a bad hard drive, or the hard drive may not be connected correctly. If you have recovery disks, you can replace the hard drive and reload the system. If you do not feel comfortable with this, I would suggest you contact technical support in your region, to inquire about repair.
Own a Predator Laptop? Then I bet you have learned a thing or two from beststevie. He has been helping out in this forum for quite a while and it's about time we recognized him for it. Thanks beststevie!