I recently downloaded a copy of Paint.NET. This is a free open-source photo editing application originally created as a student project in 2004. It was designed to replace Microsoft Paint, which was included in Windows, but has evolved into a viable alternative to Photoshop. It has a lot to offer graphic designers, web and digital artists as well as digital photographers who desire to enhance the quality of their work.
I find this to be a really useful tool. Download a copy today from http://www.paint.net.