Hi Alan,
You and others may not know about a web site run by a chap called Gizmo at
http://www.techsupportalert.com/
In it he professionally reviews hundreds of software programs that are FREE and gives an unbiassed report on each.
Now, if you are prepared to spend some time exploring the site, there is a lot in it, I am sure you will find something to suit your purpose.
I do not know if you are after something very basic to do simple basic photo retouching or something more elaborate.
I use one called "paint.net" which is half way towards a fullblown program such as photoshop.
As mentioned the advantage is that you can try as many as you like without running up a bill.
I have obtained all of my software from here except Win7 and Office and if/when they go phut I will be downloading something free to replace them both.
I hope this is of help.
Rgds