procedure TForm2.ShowExeIcon(const AFile: string;
  const AIndex, AIconSize: Integer; AImage: TImageEnView);
var
  hIcon: THandle;
  nIconId: DWORD;
  Icon: TIcon;
  iRGB: TRGB;
begin
  if PrivateExtractIcons(PChar(AFile), AIndex, AIconSize, AIconSize, @hIcon,
    @nIconId, 1, LR_LOADFROMFILE) <> 0 then
  begin
    try
      Icon := TIcon.Create;
      try
        Icon.Handle := hIcon;
        AImage.Clear;
        AImage.Bitmap.Assign(Icon);
        AImage.EnableAlphaChannel := True;
        iRGB := AImage.IEBitmap.Pixels[0, AImage.IEBitmap.Height - 1];
        AImage.Proc.SetTransparentColors(iRGB, iRGB, 0);
        AImage.IO.Params.BitsPerSample := 8;
        AImage.IO.Params.SamplesPerPixel := 4;
        AImage.Update;
      finally
        Icon.Free;
      end;
    finally
      DestroyIcon(hIcon);
    end;
  end
  else
  begin
    //
  end;
end;

ShowExeIcon('%systemroot%\system32\imageres.dll', 74, 32, _imgLargeIcon);