Why can't i get sound through my tv after installing windows 10?

[Windows Central Question]

Normally i watch movies and music through my tv (which i use as a monitor) and i use head phones when playing games. Now i can't switch between the two, when i switch to monitor it wont work and sometimes it says device is being used by something else.

Also if ya got time a second question. When i plug my iphone into the my computer it pops up if i want to load my photos to the computer since i updated windows it never works.