An AV I used to use was Webroot Spy Sweeper: http://www.webroot.com and I think they have a free version somewhere which is quite good for scanning and removing viruses/bugs/worms (etc). The old version I used to have once your free trial expired would still let you scan you harddrive fro possible threats which is always nice. My current AV at the moment is non-existant, I used no AV