Leo says the hard drive is the problem. Alana could boot from a USB key just to get it running and then restore from one of her backups to a new hard drive. She could also take the computer to the Apple Store and let them do it, but she should make sure Apple gives her the old hard drive back. All hard drives can get bad sectors. Another thing she could try is running a program called SpinRite, but that is about the same price or more than getting a new hard drive.