Recognizing external drive after internal disk upgrade

The internal disk died and I replaced it with a unit I found on Ebay. The new drive came pre-formatted for my Tivo series 3 HD. I left my WD external drive unplugged, installed the new internal drive and went through the setup without a hitch. Next I plugged the external drive and Tivo detected it but it said that it needed to be setup which I authorized with the three thumbs down. The Tivo rebooted but the external drive is still coming up as if it has just been detected and Tivo is asking me to go through the process of adding it again. I tried this a few times with the same results :-(

I saw instructions on this site stating that I need to remove the internal drive, attach it to a PC and run some program to "enable" (I'm guessing) adding an external drive. Unfortunately I don't have a PC so before I find one and go through all that, I want to make sure this will indeed take care of my issue. Maybe I have a different problem. Thanks.