answer:I have it installed, but have only used it a couple of times. I usually use CCleaner. It seems like even the free version of ASC has a lot of features (with add-ons you can download to further system optimization). It’s hard to tell exactly what it’s doing because there doesn’t seem to be an option or a log to review what it’s finding as spyware, for example, or what registry changes it’s making. It was reviewed on CNet pretty favorably. Both the editors and the users give it 4 out of 5 stars.