Not Change Desktop Background from server

Hi all,
By manager of IT changed desktop background of clients.This change not any problem in windows xp on clients and desktop background of clients changed(windows xp).

But i have Windows 8.1 on my computer(as a client) and this changed not happened.

Note : Picture selected by manager IT show in list desktop background on my system and this checked but not applayed.Pictute location for this picture is "\\192.168.18.2\pic_desktop".also when I typed in run windows "\\192.168.18.2\pic_desktop" this opened and i have access.

please see:
2016-03-09_12-27-37

please help me.
thanks

Oh,I Deleted 'CachedFiles' Folder in "c:\users\myuser\AppData\Roaming\microsoft\windows\Themes" and then restarted my system,it solved but this action not perform by all users.What is logic solution?