There is excellent free anti-virus stuff to be had, but the problem is that you are using AOL. Received wisdom is to move rapidly away from that, and to cleanse your machine of it.
For virus protection, you could do a lot worse than download AVG Free - from
here. I've used that for some years, and not had a single virus infection since.
You also need a firewall (ZoneAlarm is OK) and spyware protection (AVG does one, not free if you want automatic updates).
There are many options for all of the above.