Hi, I have a power mac g5 its a few years old and I'm having trouble installing OS 10.5 leopard. When I turn on the computer i get a blinking ? folder that alternates showing a ? and a mac face, with a gray background. I tried putting in the start up disk ( ? folder doesn't appear with the start up disk) and it guides me through the installation steps, but it doesn't display a location to install the OS on. I also tried putting an external HD in and this does not appear as well. So, I went to disk utility and tried the figure out the problem. In disk utility, the internal hard drive is there, but not the external HD. I also tried switching Hard drive ports from a to b and this made no difference. IF you have any suggestion or solutions please post them. Thank you.