i ve followed all the suggestions in the site and my machine doesn t react. I can only start it up with the osx install system dvd. Inmediately the message of "Mac Os x cannot be installed on this machine computer appears". Then i open the utilities folder and the disk utility. Can see the hard drive and run the verify. Then the following message appears Filesystem verify or repair failed. Apart, in details you can read Invalid node structure Volume check failed Error. Can anyone give me another solution before taking it to a mac center? Thank you