Hi Linda,
I don't even know where you would begin. If you knew someone who was really a computer geek and knew how to go into the embedded information that all files contain, the original information should be there. However I have no idea how to get to this information.
You could search for hours on the net and never find it or find many examples of it if it was created using a tutorial. Who if anyone owns a copyright on it can be a very illusive thing. But just for you peace of mind, you are not using it on a commercial site, you are not claiming it as your own and you are not distributing it on a snag board so therefore if there is a copyright on it all that would happen is that the original creator might as you to stop using it and at the point you would do that as a courtesy.
Sherree