We have an I Book G4 we have been trouble shooting with mac tech support as it is under warranty. It is going back to them as everything we do does not resolve or makes another problem. The current issue is how with a screen that freezes upon boot up,(it goes all the way until main menu and then curser will not work with or without a mouse. Rapid key strokes on the key pad can sometimes make the arrow move but totally unresponsive.) The question is how do I do a hard drive back up with out being able to tell my machine to do anything?