Recently purchased SEG 160GB Ext HD USB 2.0 for backup on primary internal HD (Maxtor 80GB) Is there anyway to boot to EXTERNAL HD. Am running XP2, with 1gb ram. BIOS is Phoenix 3.24. Not much point in having a backup drive if I can't boot to it in case of a disaster. Anyone know?? Current versions of Windows should not be installed to USB hard disk drives because Windows does not support USB hard disk drives as the primary boot device.

http://www.microsoft.com/whdc/device/storage/usb-boot.mspxThe point of having an external drive is so that you data is safe if the computer fails.  You can MOVE it to another pc, plug it in and go.

So the next THING is, what if the external drive fails, where is the backup of your data then?

FWIW, one of the reasons you can't boot Windows from a USB device is that when Windows initializes the USB channels, you lose the connection to the device for long enough to throw it a curve.    You can boot things like MS-DOS from a USB device as long as the BIOS supports USB boot, since the BIOS is handling all the I/O to the device.Wow! What a great forum. Thanks to everyone who responded. Since it is apparent the USB Ext HD cannot be used as a boot drive, are there any work-arounds where I can still use the ext HD as a back up and  boot from another source, or do I NEED to go to another internal HD?Thanks to everyone... :-/You can boot to a floppy disk which contains the drivers for the external USB hard drive.  You can then run Norton Ghost from the floppy disk and create a disk image to backup to or restore from the USB drive.

http://www.symantec.com/sabu/ghost/ghost_personal/
I use Acronis True Image, which will GENERATE a very complete boot CD for recovery.  I do regular image backups, and if the wheels ever fall off, I boot the CD, point to the latest image, and restore it.  All done in minutes.