I have a computer illiterate friend who needs assistance. She just ran some updates on her Macbook (and of course, she doesn't know what she updated), and now she says she's unable to drag-and-drop items onto her desktop, and that her background is now gone.

Seeing as I'm 830495634 miles away from her, I can't fix it in person. I was wondering if anyone had any experience with this/solutions to this problem. Thanks