It's their job so add it to what you want put under control. In the meantime, read this.
https://www.google.com/search?q=disable+windows+change+background&ie=utf-8&oe=utf-8
It's a setting your IT needs to change.
I am in charge of the high school computer lab. We are having a problem with students changing the background display to inappropriate backgrounds. I can't monitor the lab all the time because I have other classes to teach. Is there a way that I can find out when the display was changes?

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