i'm hoping someone can help me, someone at work has an ibook and it won't startup, folder with question mark. so i tried holding the option key at startup, nada. i tried a few things, the disk utility on the jag install disk for example, didn't even see the HD. the only way i've even been able to see it, was booting from an external firewire drive. and then i'm told that the disk is having trouble mounting, use disk utility and run first aid. which i do. and all i get is this.... Repairing disk "Macintosh HD" Checking HFS Plus volume Invalid extent file PEOF Repair completed. and this takes all of half a second to complete. anyone have any ideas???? thanks guys!