Windows as supplied doesn't do that from firewire or USB connected drives. It can however from SCSI or SATA drives.
Linux however will boot and run from almost any media connected with USB and more.
Bob
have Dell Dimension E521 XP - bios shows usb as option in booting sequence. Only had computer for a few weeks - norton ghost created a new partition and then would not boot from that partition and had the pleasure of the death screen. That issue has been resolved but now with Vista upgrade - would like to purchase a WDG1U2500N which matches the 250gb capacity of my current drive --- for two reasons - to retain the possibility of running XP (it is my understanding that the vista upgrede removes XP) and to make the recovery from upgrading to Vista as easy as possible. And I thought that running an old WIN98 machine was a pain in the ***?

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