What makes helping difficult is that we cannot see or touch the computer and have to rely on the information given. In this case your description leads us to believe that your daughter hit some key to make the changes that you described, which may be the case. The story gets more interesting with the additional information about the restore.
Thinking a bit outside the box, possibly she went to a site that gave you a virus or malware.
Run you antivirus full scan
Download and run malwarebytes. Make a full scan but be sure to update it first.
In addition this problem seems very similar to yours and possibly may be a fix. I give this warning, however. I personally do not like to tamper with the registry. Unless you are proficient in that area, problems can occur. I have not tried this fix and know of no one that has but I merely present it for you consideration. http://www.winhelponline.com/blog/ca...wallpaper-fix/
That being said, I would only use the second suggestion, involving the control panel, which is specific for Vista, but then again, I have never needed that fix and am unfamiliar with the consequence.
To back up your registry http://www.vistax64.com/tutorials/21...p-restore.html