How do I change windows media player 11??

I have recently downloaded songs from youtube and put it into my windows media player 11. It registers it as unknown so I manually put the artist and album info in it. A second later it changes it back to unknown and how it was originally, how do I fix this?????How do I change windows media player 11??
im guessing media player is unable to read that format.. it has nothing to do with the ACTUAL file.. it's unknown because it is unknown to media player, to to play the file... convert it to wmv format from what ever format it's in now.. google ';music format converters'; or something like that..