I'm sorry but Malware Bytes Pwns ALL!!!!!
http://www.malwarebytes.org/mbam.php
Super Light on resources.
Free download does all you need to do.
Has saved me from so many Spyware, malware, trojans and virus that I just don't care if I get one anymore, they are a joke HA!
In fact scan with it right now and it might find something to kill for ya.