You can use standard password protection, but that would only give you a
single password without any name. Alternatively, you could use VBA to do
most of what you want. First, I would put the presentation in Kiosk mode
so the user can't jump around. Next, I would put a button on the second
slide that says something like "Click here to continue." This can
activate a VBA script that asks for a name and password. The names and
passwords could be kept in a text file, but that seems a little too
obvious for your users to find. I would probably store them in the
presentation, either on a hidden slide or using tags or something.
--David