Mark: if you have a MacIntel machine, you can boot from a USB2 drive. The drive has to be formatted with a GUID partition. If you have a PowerPC Mac, then you can only boot off an external firewire drive. Note that the hard drive must be formatted using an Apple partition map. To be sure it would work, I would create the drive in a firewire enclosure and make sure it boots, then slip it into a USB2 case. If you clone to the USB2 case, you will be flying blind (all fingers and toes crossed) as to whether it will work later in a firewire enclosure. But it "should" work. The one other thing is that clone you make for a PowerPC Mac will not boot on a Macintel machine. Hope this helps. Jeff On Dec 17, 2008, at 6:32 PM, Mark Des Cotes wrote: > I know I can't boot from a USB2 external drive. If I make a clone of > my HD to the USB2 external drive using CCC, could I, if the need > ever arises, take the drive out of it's enclosure put it in a > FireWire enclosure and boot from it? Or do I have to make the clone > directly to a FW drive? > > Mark Des Cotes > Owner-Graphic Designer > Marksman Design > ----------------------------------------------- Carruthers Communications Tel: 520-625-1913 292 N. Camino del Vate, Green Valley, AZ 85614 www.carruthers.com e-mail: jeff at carruthers.com