There should be a setting to shut it off. I haven't used it for years. In fact, I thought they quit making it. I do know there was a setting to shut off the defrag at boot up because I had it shut off myself, as it brought the boot up to a crawl.
Let me also warn you to be careful when using that program. It can and will damage your system. I couldn't count how many times I had to do repairs after running it.