Need help, badly i guess..?

played my windows media player last nyt (bout 8pm local time +gmt), then after an hour or so, i decided to turn my pc off, off course shutting down the player in the usual way. when i turn my pc on today and decided to use my media player, all the songs, video are gone...what do you think happened to it? tried looking at my recycle bin maybe i accidentally erased everything, but its not there..im not so sorry about the songs, its more on the vidoes saved in it..