A-Squared Free has been updated to v4.5
There are two (free for private use) options:
1. The regular A-=Squared anti-malware package.
2. Including "Online Armor" from the unlikely named "Tall Emu" :D
Online Armour is a combination of a firewall and a program/process guard. It seem s quite easy to use and a better option that ZoneAlarm free edition. This is particularly true if you have Windows 2000, which is now no longer supported by Zone Alarm.