Check if your Mac computer meets the minimum requirement below:
Mac G3 or higher with: Mac OS 9 – OS X
CD-ROM drive (for encoding from CD)
96MB available RAM
Several USB Mass Storage class drivers may not be available in the upgrade version of the OS. Make sure that you have USB Mass Storage Support version 1.3.5 or higher installed on your computer. If you have not already done so, download the USB Mass Storage Support 1.3.5 from the Apple Software Updates web site http://www.apple.com/support.