Avidemux - save video problem

I captured a vhs tape in avi, managed to sync ok, then file/save/save video(video-copy) & (audio-copy) only part of the video was saved plus 17 files that Windows didn’t recognise & equal in size to the main file.
I tried to to save in dvd(lac) & dvd(mpeg2enc) but threw up warning that it was wrong format
Can anyone help - many thanks
PS: am computer literate, but new to video editing etc!