Tyler1989 said:flame me if you wish but spybot and ad aware are terrible. Go with windows defender if you want a free app.
the Windows Defender name now belongs to Microsoft.
Last I heard, Microsoft shut them down and took the name for their own product line.
Also, worth a read - I use Avast!, Kerio PF, Firefox + all the extensions listed there (love your icon BTW) and Spywareblaster... with that I have essentially eliminated the need for a spyware scanner, as I've been fully spyware-free for over a year now.
EDIT: Yes, I am referring to a different "Windows Defender," which had been a good program at one point before Microsoft shut down the nonprofit developer with lawsuit threats over the name. I won't use Microsoft's version for the obvious reasons.