UV Texture image files

I do not understand why, if I have opened the image in the UV/Image Editor, loaded the image in the texture channel, and loaded the file in the Image panel of the Texture Mode, it has to be re-loaded when I restart Blender. A black swatch remains in the place of the texture image. I have to re-load them everytime I start Blender and a new model. I don't want to save the model as a default setting, so how do I save the images but not the model after loading them and texturing a model?