Could someone please help? I am new to Mac and just totally lost. I have an IMac G5 and when I start up, I just get a blank blue screen. Apple shipped me a replacement start up disk, and told me to do a repair. I did disk repair as well as a permissions repair. What do I do now? Do I force quit and try to restart? If so, I still get the blue screen. Do I need to do something while I am in the menu to reboot? Thanks in advance!!