You will have to give them a recommended list of USB drives that will work
via "server side installation" that used signed drivers and has been tested
and shown to work. The link below explains more. It talks about USB
printers but the concept is the same. --- Steve
http://support.microsoft.com/default.aspx?scid=kb;en-us;326473
Server-side Installations
A server-side installation is a device installation that is performed
entirely by the Plug and Play manager. A server-side installation can occur
only if the following conditions are true: . A bus driver detects the device
and notifies Plug and Play Manager.
. Plug and Play Manager finds an .inf file that contains a hardware ID
that matches the hardware ID of the device.
. The .inf file and the drivers for the device are signed.
. Windows XP can locate all the drivers for the device without
prompting the user for media locations (for example, the drivers are
included with the operating system, a vendor-supplied driver was previously
installed, or vendor-supplied driver files are preinstalled).
. The class installer and co-installers for the device do not open
properties at the end of the installation.
. The .inf file for the device does not indicate that the device
requires an interactive installation.
. RunOnce registry entries consist only of calls to the Rundll32.exe
file.
A server-side installation does not prompt the user for any additional
information and does not require administrator credentials. This type of
installation is known as "server-side" because the installation is performed
by Plug and Play Manager and interaction with a user-mode client is not
required.