is it possible in mp3tag software to change "windows media player or vlc "file icon change with our favourite cover image..
I doubt that this has anything to do with mp3tag but is a feature of the underlying OS. You dump looks like Windows XP - and that can't do it AFAIK.
Windows 7 displays the covers (from within the files) when the Explorer display is set to symbols.
You could redirect your question to a Windows forum.
No.
I guess, you will need the windows system itself for this purpose.
I think you have to change the current file association to another application.
Maybe ... see explorer, folder options, file types ...
DD.20120201.2106.CET