Monique, I see what you mean. That checkbox at the bottom is where to save the supplies you CREATE in PSP. For example, if you export a Picture tube, or a Brush, or a Preset. However, you don’t SAVE plugins as you are not creating them. That is why you don’t have that particular checkbox. By listing the location on the top, it tells PSP where the plugins are located on your computer.
Does that make sense?
