Problem
The desktop image must be changed
Solution
Use a low-level Windows hook to set the background
Sample Code
(:source lang=C#:)
[DllImport("user32")]
static extern bool SystemParametersInfo(int uiAction, int uiParam, string pvParam, bool fWinIni);
const int SPI_SETDESKWALLPAPER = 0x14;
// in code
// ensure fileName is a bitmap (of the format ImageFormat.Bmp)
SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, fileName, true);