Title: How to make a round window
procedure TForm1.FormCreate(Sender: TObject);
var
R: HRgn;
a: integer;
begin
a := -25;
Height := 500;
Width := 550;
R := CreateEllipticRgn(-a, - a, Width - 45, Height - 45);
SetWindowRgn(Handle, R, True);
end;