I didn't know about that recently...but someone give me this hint that I would like to share.
When recording a video....the extension of the file is *.dm.82
so this file can't be read to normal video player..like VLC or Media Player etc...
cause in fact these kind of file are crypted files who contain coordinates points allowing ET to use it and run.
that is why they are few kb only.
So to open these files..you can open ET and at the MAIN menu....select REPLAYS button.
All dm.82 file must be in your ET installation folder under
...(ET installation folder)\silent\demos\*.dm.82
I've bind F10 key to record...by changing the etconfig.cfg file in my ET installation folder.
bind F10 "autorecord" or you can do it via the ET menus...
I hope this will be useful for someone.