strComputer = "."
Set objWMIService = GetObject("winmgmts:" _
    & "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")

Set colItems = objWMIService.ExecQuery("Select * from Win32_Desktop")

For Each objItem in colItems

    Wscript.Echo "Wallpaper: " & objItem.Wallpaper
Next