Computer Won't Recognize Hard Drives - "Tuff Test", Running At Boot Up

The Dell 8250 Pentium IV computer will not recognize the new master 160 GHZ or the origional, now slave, 40 GHZ, Hard drives. All the connections and jumpers are installed correctly. I tried a new motherboard and a new cable, both did not resolve this problem. Even ran a diagnostic program called "Tuff Test", running at boot up and the RAM and all other items checked OK, showing all working properly. The BIOS, now set to boot up correctly, off the proper drive, seems to recognize both removable drives and the floppy, but not the hard drives.
When I received the computer it was password protected. after asking and waiting for a week, with no response, I therefore, in safe mode,entered the BIOS and chose for it to boot off of the CD Rw that I thought was the proper and shut the Hard Drive off. Here the CD RW was a slave and not the master. No luck in installing the OS. I bought a new 160 GHZ HD with the thought that I could load the OS, again no luck. I replaced the battery and tried again with no luck.