Okay, I got this iMac off an auction- it's just the base, no software. I'm trying to update the firmware, but when I try (with an OS 8.6, 9 or 9.1 CD) it says that it cannot copy the needed files to a locked volume. In other words I need to have the OS already installed. How can I install the OS if the firmware update is required BEFORE INSTALLING?? Is there any way around this?