Whats wrong? Everything?
Hard to tell without more info. What .img did you download exactly, cn or cx, locked or unlocked? Is it locked & you haven't unlocked it? Try re-reading the earlier posts in this thread and look at [Only registered and activated users can see links. ] and for CX use with 3750 [Only registered and activated users can see links. ]. Post again with full info if you're still stuck.