Hey Lakedude,
Thanks for your help so far. I managed to read the file into the original application which produced it & then get it to change it into an executable that will run on its own. This will do the trick for the moment.
just for your info, the SMV file turned out to be a Smith Micro Video file, the company that make Videolink mail. No wonder no-one had heard of it.
Anyway, thanks again,
James