White to Play and Win
There is nothing wrong with your moves. You just revealed the art of chess like many composers. The king is boxed in and pawn is about to queen. Good Thinking!
You found the correct promotion (under promotion).
I've posted a fixed version of this puzzle here:
http://www.chess.com/forum/view/more-puzzles/protect-the-escape-route
The king would take your lone pawn
THE QUEEN SACKS AND THE BISHOP SACK ARE UNNECESARY, BUT THE COMPOSER ONLY WANT TO SHOW THE BEAUTY OF THE PUZZLE. LOOK AT THE KING HIS GOT LOCKED UP WITH HIS OWN ARMY AND BEING MATED WITH A KNIGHT IN SHINING ARMOR.
My mistake -- I didn't link to a fixed version (I got my threads mixed up)
I believe that this fixes the problems with the original puzzle: