Mac OS X 10.3 or later: System won‘t restart after installing SUIExtras.pkg

If you install the SIUExtras.pkg on Mac OS X 10.3 or later, it will prevent your system from restarting.

This package is used by System Image Utility for creating Mac OS X 10.3 NetInstall images; it's not meant to be installed under any circumstances. The package's /etc/rc.cdrom file is the item that prevents your computer from restarting because it tries to force the Installer to launch. You can resolve this issue by removing the file as follows:

1. During startup, press and hold Command-S to start up in single-user mode.
2. Type each of the following commands, pressing Return after each one.
   Warning: Be sure to type the commands exactly as they appear below. Misusing the "rm" command can cause unintended data loss.
   

   fsck -yf 
   mount -uw /
   rm /etc/rc.cdrom
   exit

After performing these commands, the system will restart normally. The package also installs files at /System/Installation/CDIS and /Applications/Utilities/Startup Disk.app. You can delete these in the Finder after the system starts up.