Misliš, wallpaper?

da

Pazi, ono što tebi treba jeste funkcija iz Win Api-ja. Jednostavno importuješ odgovarajući dll, a to je user32.dll dok je funkcija SystemParametersInfo.

Evo koda u vb-ju:
Private Const SPI_SETDESKWALLPAPER As Integer = &H14
Private Const SPIF_UPDATEINIFILE As Integer = &H1
Private Const SPIF_SENDWININICHANGE As Integer = &H2

Private Declare Auto Function SystemParametersInfo Lib "user32.dll" ( _
ByVal uAction As Integer, ByVal uParam As Integer, _
ByVal lpvParam As String, ByVal fuWinIni As Integer) As Integer

Const WallpaperFile As String = "neka slika.bmp"

Friend Sub SetWallpaper(ByVal img As Image)
Dim imageLocation As String
imageLocation = My.Computer.FileSystem.CombinePath( _
My.Computer.FileSystem.SpecialDirectories.MyPictures, WallpaperFile)
Try
img.Save(imageLocation, System.Drawing.Imaging.ImageFormat.Bmp)
SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, imageLocation, _
SPIF_UPDATEINIFILE Or SPIF_SENDWININICHANGE)
Catch Ex As Exception
Throw New Exception(Ex.Message)
End Try
End Sub