Try going into the computer cmos settings and disabling USB at that level
and then password protect the cmos settings. Some go to the extreme of
putting epoxy in the USB ports. Of course that would prevent all users from
using USB. It is more difficult to manage USB access by user but there are
third party programs like Device Lock that supposedly can do such. ---
Steve
Take a look at DeviceWall (http://www.devicewall.com) it allows you to
provide granular access controls at the user level. You can block
access to specific devices for users, or block all devices, even define
read/write access.