Sygate Personal Firewall has never failed me as a free firewall solution. It can be simple enough to be left alone, and it has advanced features so you can set every rule in stone. As for free virus scanners, I actually would recommend against it. If you want a real anti-virus solution, you should try NOD32. License is $40/year the last time I checked. It costs that much because it's one of the best, without venturing into commercial usage (which cost hundreds if not thousands).
Anyway, good luck
. Also, it does indeed sound like someone is brute forcing a port scan on your system. If you get Sygate, it can log the offending IP and add it to a blacklist.
