セーフモード: Safe Mode is the state Mac OS X is in after a Safe Boot. Starting up into Safe Mode forces a directory check of the startup volume, loads only required kernel extensions, runs only Apple-installed startup items, disables all fonts other than those installed by the system, moves all font caches to the Trash and disables any Login Items. Safe Mode can be useful for troubleshooting. However, certain Mac OS X features do not work when you are started up in Safe Mode. For example, you can't use DVD Player, capture video in iMovie, use an AirPort card, use audio input or output devices, or use an internal or external USB modem.