Hi Ken
OK all understood.
Its looks like you may have the file suffixes hidden on your machine... I would expect the file to be called something along the lines of (for example)
Peterboro_cathedral.avi
Can you tell us what application/Programme you used to create the video please
also
When you double click on a video file( to open it) what application/programme opens? and does the video run OK from it?
Regards
paws
PS to show file suffixes see here