Computer can't find startup drive

My father has an iMac G3 Indigo, indigo color, the model that is newer than the iMac DV's, that recently on startup shows the flashing file/iMac icon--it can't locate a startup drive and the HD is clicking during its attempted startup. I've bailed out systems like this in the past by reloading software. Luckily I was able to locate the computer's original software CD collection. I ran its Apple Hardware Test CD which indicates that everything is OK and the HD is at the address ATA Bus 2; ID 0. I then booted the computer with its; (1) Mac Software Restore CD, (2) Mac OS 9 Install CD, and (3) Mac OS X Install CD--none of them can find the hard drive, so there is no place to restore or install system software. Methinks the HD isn't functioning correctly and may be effectively dead. Any ideas? Maybe I am missing something...it's been years since I had to deal with this problem on one of these machines. Thanks!