I-tunes doesn't work anymore

My itunes doesn't wory anymore after i moved my computer to another room (don't think that would make any differnece), anyway, my limewire came up with some popup saying itunes doesn't work, and i was racing through and just clicked on it as if it was just an ordinary update or whatever and i realised that it was itunes.

Anyone that has a clue what i'm talking about, please tell me.