You don't need any special software to make your pics as small as you want. If you have Windows, then you have Paint. Pull up your pic in Paint (or send to Paint), at the top click "Image." Then click "Stretch/Screw." Then pick "Stretch." You'll see "100%" in both horizontal and vertical. Change that to any number less than 100. Be sure to change both horizontal and vertical to the same number. The smaller the number, the smaller your picture will be. If you pick 50%, for example, your pic will change to half the size. If you like it, you can save it, either "save" to completely replace the original, or "save as" and give it a different name to save the smaller one and keep the original as well. If you don't like the size you've made it, click "Edit" and "Undo." Or just get out without saving and start over. You can do lots of stuff with pics in Paint. Oh, btw - you mentioned eBay. You don't need to compress or make photos smaller for eBay. EBay does it automatically when you put them on there.
