I'm going with what mostly everyone said and go with AVG. It'll do the automatic scans, and since the scans can slow down your comp some, I usually pause the scans while I'm working on something, and then let it run while I go and eat, do the dishes, go watch some TV, or whatever. It works great and has caught a few trojans. It also automatically vaults any small trackers it finds, so you can easily clean out the vault and feel very very safe. Plus, Norton is terrible.