I use ZA free firewall for home use, and it has been excellent.
However, I was startled to find that something I had dowloaded or software I tried out has wiped out the trusted zones on my laptop, so the home network was compromised.

I had to re-enter the zones manually to get back to normal.

Operating System:Windows XP Pro
Software Version:8.0
Product Name:ZoneAlarm (Free)