A small question about song album covers

I can't seem to put an album cover for a certain song even if the pic is inside my song folders.Can anyone help me?

You have to put it into a special folder (mine is "covers" in the "Music" folder). There you have to put every cover and then you have to edit the album covern and select the correct one by yourself.

I found the Cover folder inside the Music folder.But i noticed that all the images are to be in .thm format.I tried searching on google to find converters which can convert JPEG to THM format but i cant find it.Can you please teach me how to edit them into THM format?Thanks