I don't want a precise answer, but as some of you know, when you insert an USB drive, it sometimes installs the new driver, sometimes doesn't because an other drive that is sort of compatible has been used before on that same computer. It might be transparent but it makes a big difference when you don't have admin rights on the machine. Does anybody know how much "different sorts" of those USB drives are included in XP ? (maybe there's even more in SP2). Is it about 10 or hundreds ?