The ad you mentioned shows how to make a panoramic picture using Windows Live Photo Gallery, which is a part of Windows Live suite of programs. Windows Live is free, you can download it or individual parts here
So as you have been told earlier here, there's a bunch of free image editors available. For my basic needs I use Windows Paint and Live Photo Gallery, for some more advanced stuff Paint.net
(also free) or Adobe Photoshop
which you can test 30 days for free.
Even Live Photo Gallery is not an editing tool, you can do some nice things with it. Here's a couple of examples what Live Photo Gallery can do, unedited panoramas of our village a few days ago. Each is made from 4 to 6 photos. If I would like to edit them, I could do it also with Windows Paint. It is a free application which comes with Windows: