You might want to take a look at the SystemParamertersInfo API. A sample would be something like the following:
Public Declare Function SystemParametersInfo _
Lib "user32" Alias "SystemParametersInfoA" _
(ByVal uAction As Long, ByVal uParam As Long, _
ByVal lpvParam As String, ByVal fuWinIni As Long) _
As Long
FileName = "C:\...\...\YourImageFile.Ext"
Ret = SystemParametersInfo(SPI_SETDESKWALLPAPER, 0&, FileName, SPIF_UPDATEINIFILE Or SPIF_SENDWININICHANGE) Good Luck
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As a circle of light increases so does the circumference of darkness around it. - Albert Einstein