Thanks for that. May I now submit a suplementary question?
When I was tidying up my files I found 17 files in a group called, "Index File" the first of which was called, "Video 1.avi.A.index.
The second group of files was in a group called, "SCN File" the first of which was called, "Video 1.scn"
Are these important or can I dump them?