I backed up my data onto an external hard drive then performed erase & install. the issue i have is that some of the music files I have moved back to the computer are missing album artwork sometimes just a single track in a whole album or half of an albums tracks. I haven't found one complete album missing the artwork just various tracks in a few random album folders. I don't know if there are any of tags or data missing such as comments or lyrics. why has this happened and how safe are keeping tags and artwork linked to a music file? should I include the album cover and lyrics in the album folder in case of this happening again?