Firstly I put my VHS tape videos on to an external drive which showed, via WMP, the MPEG2 files' thumbnails as the first image of the recording.
As VLC is promoted as more flexible I changed the default app to VLC to try it . That is OK but the thumbnails are now just the 'traffic' cone icon.
Wanting to return to WMP to get those image thumbnails back I changed the default app back to WMP but the thumbnails only show the icon 'MPEG' with no images.
The next time I opened the drive the icons were back to VLC cones! Any explanation for this please?
Win 10 and all icons have their separate names.