procedure TForm1.Button1Click(Sender: TObject);
var
  Picture: TPicture;
  Desktop: TCanvas;
  X, Y: Integer;
begin
  Picture := TPicture.Create;
  Desktop := TCanvas.Create;
  Picture.LoadFromFile('bitmap1.bmp');
  Desktop.Handle := GetWindowDC(0);
  X := 100;
  Y := 100;
  Desktop.Draw(X, Y, Picture.Graphic);
  ReleaseDC(0, Desktop.Handle);
  Picture.Free;
  Desktop.Free;
end; 