Hello, my original drive was making terrible noises and I couldn't even reformat the drive. So I bought a new drive. I did the complete process to install the drive and the computer did not come up at all. I re-installed the original drive and the computer started up fine the first time. The next time it would not start. I reset the PRAM and from then on the computer does not recognize either one of the drives, it does not show the hard drive during OSX installation. Neither the original drive, nor the new drive.
Thanks for your advice.
Peace
Erich