To still protect your Mac from starting on untrusted external media, you can set a firmware password, available on macOS Mountain Lion or later. A firmware password prevents users who do not have the password from starting up from any media other than the designated startup disk.
<strong>If you forget your firmware password you will require an in-person service appointment with an Apple Store or Apple Authorized Service Provider.</strong>
The <b>Troubleshooting Mode</b> entry disables some features of the Linuxkernel and might work better on some computers. You can try this option if you think you are experiencing hardware compatibility errors while starting Tails.
The <b>External Hard Disk</b> entry makes it possible to [[start from an external hard disk|doc/advanced_topics/external_hard_disk]] and some [[problematic USB sticks|support/known_issues#problematic-usb-stick]].