Fortunately, there are some relatively straightforward methods for dealing with this issue. This obviously makes re-installation of Mac OS X impossible, and severely limits your troubleshooting avenues. You grab your Mac OS X CD or DVD, insert it, press the reset button, hold down the 'C' key and expect to be back up and running - but the system still refuses to properly boot. It's a troubleshooting nightmare: you have problems starting your standard Mac OS X installation, or another serious issue that requires re-installation of Mac OS X itself.
