The following are our suggestions for maintaining a healthy PC. These are not the only ideas and there are many other products available to do many of the tasks mentioned, however those below actually work!
Refer to this article
What about Windows XP Firewall?
This is even better Windows XP Software Patch 2 - refer to this Microsoft Article
Yes - Zonealarm has an excellent Software Firewall. The even have one that is free to individuals and non profitable charity organizations.
Refer also to SpywareAid for other Firewalls
refer to this article