My game won't maximize

Okay so I downloaded Wrath of the Lich King with the new models but my game won't maximize
I click it and the login music starts playing, then it stops, like it's there, running, but I can't see the screen, so the music won't go out either.
I already had this problem with Smite, but I fixed it reading some threads, I hope you can help me

-----------
So here I am, 2 minutes later just to say I fixed it.
As the game came from "another computer" and it was "not trusted", I had to unblock (?) it, make it trusty, then the game maximized after I applyed the changes and opened it again.
Sorry, I don't know how to delete posts, but well, here is the solution
Such nostalgia this dragon flying, wow