Why does my Apple ID password not work on my iPod after a reset

Can not connect to wi-fi older model locked up have gone on net unlocked it but now wont unlock I-pod reset to factory settings changed password on apple site, can get in to apple site on computer with password but i-pod still says wrong password, did every thing I can think of tried other places like library thinking it may be my wi-fi still the same results apple id password pops up after putting password in

[Re-Titled by Moderator]