What do I do if the internal drive won't boot, but on booting the utility CD and going to Disk Utility, I can see the...

What do I do if the internal drive won't boot, but on booting the utility CD and going to Disk Utility, I can see the drive, but the "Verify Disk Permissions" and "Repair Disk Permissions" buttons are grayed out? The "Verify Disk" and "Repair Disk" buttons are useable, but they both simply run through their checks and come up clean?