用默认浏览器打开,uses shellapi}
procedure TForm1.Button2Click(Sender: TObject);
begin
ShellExecute(Application.Handle, nil, 'http://www.3464.com', nil, nil, SW_SHOWNORMAL);
end;

{以下三种用IE浏览器打开}

{uses shellapi}

procedure TForm1.Button1Click(Sender: TObject);
begin
ShellExecute(Application.Handle, 'open','Iexplore.exe','http://www.3464.com',nil,SW_SHOWNORMAL);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
ShellExecute(Application.Handle, nil, 'http://www.3464.com', nil, nil, SW_SHOWNORMAL);
end;

//uses SHDocVw;

procedure TForm1.Button4Click(Sender: TObject);
var
IE : OleVariant;
begin
IE := CoInternetExplorer.Create;
IE.Visible := True;
IE.Navigate2('http://www.3464.com');
end;