I have a memory stick that I picked up free at a conference. It's only
got the presentation on it, which I don't want, so I'd like to use the
stick for routine purposes. However I can't write to it, although the
write protect tab is off. When I try to reformat it I get "Invalid media
or track 0 bad - disk unusable".

Obviously locked somehow by the people who distributed it. Any ideas for
unlocking it? I don't know the manufacturer. Google is no great help.

--
Les