Any idea why the only way I can get my MAC to boot up is to reset the PRAM?

I have a PowerMAC G4. It had OS X. The hard disk went south, so I had to replace it. Unfortunetly, the MAC is used and I did not have an install or restore disk. A friend of mine gave me a eAMC OS 9.2.2 install CD.

I ran the install without a problem, but now I get the disk with a "?" mark blinking at me. I found out that this could be a problem with PRAM and it could be set to factory default by using CONTROL-OPTION-P-R.

I did, it booted up. But when I rebooted, I get back to the blinking "?" mark.

Any ideas as to what I am doing wrong?

Thanks