I just installed a WD 120G in my G4/667. I think it's formatted for a PC, the installation software is all PC. When I put in the hardware, the instructions gave me 2 options..if CSEL is enabled on IDE bus, they have the jumper..all the way to the right. They said, if not sure of CSEL, then they showed the jumper for a "slave" drive..that's what I did. So, I power it up & the Mac G4/667 booted up fine.. (this seems to indicate the drives are not conflicting). Except, the drive doesn't show up on the Desktop. When I do System Profiler, it shows up as "ID=1 Hard Drive No Volumes mounted". Does this mean I have to format it as a Mac drive..is it just using DFA (Disk First Aid), or some other Mac system software program? Sorry about the basic question. Regarding good disk utilities, can someone recommend a good one? A long time ago, I remember a FWB (?) or a LaCie as good ones. (there was another one, but I forgot its name) TIA for any help/advice.