procedure TfrmMain.Button1Click(Sender: TObject);
begin
With TOpenPictureDialog.Create(Self) do
Try
InitialDir := '%USERPROFILE%';
Filter := GraphicFilter(TBitmap);
If Execute Then
SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, PChar(FileName), SPIF_SENDCHANGE);
Finally
Free;
End;
end;