Horn , power windows and sunroof all stoped working on 2007 changed horn fuse and as soon as i used the horn the fuse blew again

This wold indicate that you have a shorted horn circuit. Generally, the horn circuit has a negative contact at the steering wheel, meaning when you push the button, it grounds (-) the sysem causing the relay out in the engine compartment area to provide 12V (+) directly to the horn. If nothing else causes the fuse to blow, the pwr window/sunroof., then either the relay itself is shorting out or a wire to the horn is grounding, or you have a bad horn. (spend a few fuses & save time, unplug the relay, replace the fuse & press the horn button & see if the fuse blows. Next, plug in the relay & do the same for the horn)

Generally it won't be the wire from the horn button or the horn would be working continually. Your owners manual should tell you where the relay is & you could see if you notice any unusual appearance to the case, as well as following the wiring from there to the horn, to see if any damage is apparent. IE: if the horn is located in the front grill area or near a opening in the fenderwell, does it appear a rock or something has hit it or any wiring causing damage. With a vehicle as new as yours, if it isn't obvious damage, I would suspect the relay. good luck