Ok, yesterday I swapped one hardrive from a g4 400MHZ and a G4 500MHz. I took out the main drive from the 500MHz and put it in the 400, and i took the 80GB Master from the 400 and put it in the same spot as the 500. The g4 500MHz has 4 hardrives in it and one controller card. The problem is only with the 500, so forget about the other machine. Ok, on the controller card in the G4 500, there are 2 IDE ports. I have two hardrives connected to each port. On each of the two cables, one drive is set to master, the other is set to slave (through jumper settings). I boot up, and it starts booting up not off the drive I had just put in, but off another drive in the computer that had OS 9 on it. I put in my OS X Jag CDs, and begin to reformat that drive. I reinstall X, and it boots fine. Once I am in X, I change my startup disk to the original drive I put in my computer. I boot up...no problem. Now I want to reformat my main disk. I then go to disk utility and erase everything on the drive that I had just installed X on. So now I have 4 drives. 3 with no OS, and one with OS X. I copy over my main files to the drive that had just been erased, and then I boot from the X CD. I install OS X, and the machine asks to reboot. I do, and then that screen that is white with the gray apple logo sits there. The black circle is spinning for about a minute, and then the gray apple changes to a gray circle with a slash in the middle. I reboot again holding down option, same thing happens. I boot off the X CD and open disk utility there. It is telling me that I have two master drives (one is the drive i erased the contents of, the other is the one i just installed X on). The other 2 drives are slaves. I try installing X again (I use the erase everything each time), and still no go. I shut down the CPU, and unplug all IDE Cables except for the one with the drive I want to use. Still, no go. I have tried changing jumper settings, swapping cables, everything, but I get the gray apple slash *of death* each time. Could someone PLEASE help me out?