I just replaced the HDD for my powerbook G4 12", by my self. I restarted the computer using the CD that came with the machine when I first bought it, and when I reach stage number 3, when the system ask where do I want to install the OS, I get no choice. there is no hard drive appears so I can choose it.. I disassembled and assembled the machine several time to make sure that I didn't miss up any thing, but I kept getting the same problem..!!! Apple said they will fix it for $300 any thoughts plzzzzz..