I've had 4 internal hard drives in my Mac for at least 2 years now. No problems. Just two weeks ago I switched one of my drives which was in the ATA 66 front bay and set it as the master drive and it's also my boot drive. It's a 300 GB seagate. I took out a 60 GB and replaced it with a 120 GB hard drive that I had as my boot drive before, but had some problems with. My plan was to format it and use it for extra storage. That was installed as a master drive in my ATA 100 bay. At first it mounted fine and I was able to recover information from it using Data Rescue, but before I was able to format it, one day it just didn't mount anymore. Then, when I tried booting my computer it froze at the point where it says mounting
You have confused your computer with two master drives. Even though you may have two different bays, you can have only one master drive.
Reset the 120Gb drive to slave, then give it a try.
Let me know if you need further assistance.
Cheryl
Great. If you no longer need assistance, I will close this ticket.
Cheryl