Mil Shield questions

Hello I heard this was a good site to get some question's answered so here I go.....


Im using a free trial of a program called Mil Shield and I just wanted to know If I should even trust it enough to use its Free space shredder, I was wondering if its going to do something bad or not. The purpose of this shredder is to clean up info on what sites you visited that you deleted that are stuck in your free space that havent been fully deleted or something like that. Is this trustable or is there another program I should use? Im not sure Please help if you can thanks