After troubleshooting the PC, I found out the HDs (80GM WD800) & (Samsung 80GB) seem to be the problem. I have tried jumper at Master/Slave and Cable select/Cable Select. In both options, the HDs are not recognized by the POST/BIOS. I attached other HDs to the PC and it recognizes them.
Is there a way to access the 80GB HDs for data extraction & setup?