Hello , I'm new to Mac OS , i have the laptop about 3 months .... , i reinstalled leopard everything worked great and after couple of hours the computer froze i pressed the reset button and the OS won't start since . i tried to boot from the Install Disk that came with the laptop and still , i inserted the disk reset and computer pressed C nothing happened ...... tried again and pressed D ....... and again with COMMAND + OPTION + P+R ......... COMMAND + OPTION + O+F ... taking out the battery unplugging the AC and pressing the power button ...... , when i press OPTION and select Install Disk as boot i get the gray screen with the spinning logo i tried it like that couple of times even left it for 2 hours and it didn't boot . the computer can only operate if i press OPTION when booting and selecting windows partition . I'm currently using Windows and the DVD works fine i don't have any problem with windows or any hardware or the Mac OS X Install DVD . what's weird is that i can boot with Windows Installation Disk with no problems . any ideas ? Thanks Gideon .