ipod itunes and windows media player?

so i have an old version of the ipod nano. i downloaded a few songs from itunes but then i downloaed mp3s and burned them on cds then imported and edited them on itunes. i found a way where you add files from windows media player to itunes.but i deleted a few songs from windows media player and those songs on itunes wont work or stay on my ipod. is there another way to download songs from windows to itues or a way to fix that problem?

thanks alot