I have an '07 MacBook Pro running 10.5 I was on the desktop and I did a 'Command I' click on the MacHD icon to see what memory was being used and how much was available. While the window was open which displayed the memory, I scrolled to the bottom to the sharing and permissions portion and where it had the everyone box - changed the permissions to 'no access' I then logged out and shut the machine down. Now I try to start up and all i get is the blue screen with the spinning gear. I have tried to start with the shift key down, no luck. I tried with the startup disk and holding the c key then went to disk utility and did the disk repair which came back OK but the disk permission keep failing due to error of underlying task. I know I never should have messed with the permissions. Any help would be appreciated.