I am at a loss. I am unable to get my OS 10.4 Installer DVD to mount or boot my G4, currently running OS 10.4.11, though it mounts and boots other of my Macs and I am able to boot and mount a 10.1 DVD with my current Pioneer DVR-1060 drive. I would like to run a hardware test on my mac as I recently had one of my hard drives die and just want to check everything. So does not seem to be the drive and does not seem to be the DVDs. I zapped the pram, reset the open firmware and ran diagnostics using Applejack and everything checked out okay with my current internal drive. Any ideas would be greatly appreciated. If nothing else, I feel very uncomfortable having a system that I am unable to boot from my installer disk. Please help if you can!!!