I like ZoneAlarm Free for it's very easy to use, lite on my systems & trouble free.
Back when I was on DSL my modem went bad, Verizon sent me a new one (same model),
but it was pinging and/or responding to pings. As a result a hacker was trying to break into
my system, I got a pop up alerting me that someone was trying to shutdown ZoneAlarm.
ZoneAlarm held strong! Just for fun and to confuse the hacker(s) I put in a live MEPIS
Linux CD before I went to bed. They never came back.
Until your security programs are put to the test you don't know how good they are.
Avast!, WinPatrol and ZoneAlarm have never let me down.
Keep your security programs up to date!
ZoneAlarm Free 9.3.014.000 is the newest version.
http://www.filehippo.com/download_zonealarm_free/