So last night I updated my computer before I shut it off for the night to the newest iMac software update for Leopard. The update installed but then hung up when I tried to restart the computer. After several attempts to get it restarted I had to shut to the computer down by holding the power button. When I started the computer back up it brought me to the welcome screen in the Setup assistant. I tried to go through the assistant and it went through but then brought me back to the beginning. I then tried to boot up from the Leopard install disc and run disc utility for repair permissions and verify disc but that did also not help. Lastly I tried to reinstall the system again but again no help. Does anyone know what has happened or what I should try next?