The Microsoft Windows operating system families (98SE,ME,2000,XP) do not support USB2 as a boot drive or primary system drive.
The Maxtor Personal Storage 160GB and above models are not supported as a boot drive for Macintosh operating systems because of Apple file system limitations. Some Macintosh platforms allow USB2 hard drives to function as the primary or boot drive. Check with Apple to see if your computer system supports booting to USB2 storage devices.