It's free, yes. And I think it sais in it to use spybot in order to have a complete protection from spyware. If I've understood it correctlly you should have SpywareBlaster and either Spybot or Ad-aware. But I'm no expert on internet security, if you need one of those, try LadyRain <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />. I'm sertain she'll give a much more satisfying answer too.
Übereil