When Norton Disk Doctor errors out, do you remember on which test it does this?
Start up with one of the OS CD's and go to the utilitiy folder. Start up Disk First Aide or Disk Utility. That should find the hard drive. If it does not right away, go to the menu and force it to scan for drives. Have it verify and repair the drive.
Depending on what it finds, will depend on your next step.