I asked the same question about 2 year ago, to boot XP from a stick.
Even after reformatting to NTFS from FAT32, it wouldnt work!
Booting from a proper HD USB should go ok.
For some reason XP doesnt like sticks.
But Pista and 7 support USB stick drive booting. (As far as i know...)
chookhouse 01:29:54 07/22/2012 (5)
chookhouse 08:05:36 07/23/2012