Not Change Desktop Background from server

Hi all.

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

But i have Windows 8.1 on my computer and this changed not happened.

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

please see:http://s6.picofile.com/file/8242521150/2016_03_09_12_27_37.mp4.html

please help me.

thanks