The problem, at least with OS 9
is that you can delete items using Move to Trash from the File menu.
You can also use <Cmd>-Del to do the same thing.
You may need a third party product like At Ease or Macintosh Manager, the kinds of things they use to lock down Macs in a school classroom.
Tom Sinclair
Speaker-to-Suits
Bigmac wasn't an athlete. If there was an Olympic Sick Note event, he
would've won the 100 metres I've Got Asthma, the half marathon Lurk in the
Changing Rooms, and the freestyle Got to Go to the Doctor.
-- (Terry Pratchett, Johnny and the Bomb)