When you log off a Windows workstation, your background (wallpaper) changes?
There are two types of background in newer versions of Microsoft Windows, the regular bitmap background and the Active Desktop background, which is layered over the regular bitmap background.
During logoff the Active Desktop background is turned off, leaving the last selected bitmap background.
By default, when log off is complete, the background disappears because wallpaper is a user settings.
1. Use Control Panel /Display to select None on the Background tab.
2. Use Control Panel /Display to select the Web tab and uncheck the Show Web content on my Active Desktop box.