I have a G4 AGP Graphics model running 500mhz and 419mb of ram. 20 gig of hard drive. Cd rom drive. Running OS X 10.4.7. I got this from my brother and he installed a bunch of developer and server stuff on it that I don't want. I want to format the drive and do a clean install. So I have the 10.4 install cds. Put the first cd in, loads up great. Click on the install icon. It tells me to restart. I click it and the computer restarts. Only, it just loads back into the original OS that's already on it ( stated above). Try holding down and c and nothing happens. Try holding down the alt to see if it's bootable and that doesn't work. I try to change the startup, and I click on the install cd to startup from there but it the computer makes that thumpy error noise and nothing happens. How can I do a clean install and start over with this thing?