It wasn't completely clear but what I "think" it does is to clean your system of crap and give you health reports on what is on your computer and what is trying to get on to it. And evidently it is meant to be used periodically. It does not take the place of a firewall or an anti-virus program but rather augments it. And it can (and should) be used with a new computer... especially one that came bundled with crapware from the OEM.
UserAgent: Mozilla/5.0 (Windows NT 6.1; rv:13.0) Gecko/20100101 Firefox/13.0.1