Not good advice being given here at all. Ignore it. Would not bother with spybot or AdAware. AGV A/S is ok, but also not really sufficient, and should only be used as a secondary scanner. It especially does not cover even half of the area's of concern, and the free versions are NOT REAL TIME protection, which is critical. IMO, there are no good free alternatives, but if you must, consider using AntiVir.
You would be far better off using something like Kaspersky internet security suite, which is Firewall, AV, AS, and simplistic HIPS protection all in one. Very good package all round. Probably the best suite out there right now.
You get what you pay for, and with free, you don't get too much. When you are dealing with financial matters on the internet, security should not be skimped on.
