What free software should I use to protect my PC? Antivirus, firewall (if window not enough), etc.?

The best firewall available is the Comodo Firewall Pro (zone alarm is lame in comparison):

http://www.personalfirewall.comodo.com/

The best free antivirii are Avast and Avira AntiVir (forget AVG; it's junk) choose one only:

Avast 4 Home Edition: http://www.avast.com/eng/avast_4_home.ht...

Avira AntiVir Personal Edition : http://www.free-av.com/antivirus/allinon...

The best on-demand spyware scanner is Superantispyware:

http://www.superantispyware.com/

The best free real-time antispy protection is Comodo's BOClean:

http://www.comodo.com/boclean/boclean.ht...

If you want the best paid protection, that would probably be the Kaspersky Internet Security:

http://www.kaspersky.com/

What free software should I use to protect my PC? Antivirus, firewall (if window not enough), etc.?anti virus software

Consider using A Combination Of Free Programs

And Build Your Own Free Internet Security Suite.

Use One Anti-Virus, One Firewall And As Many Anti-Spyware Programs As You Want !.

Here Is A List Of Some Free Anti-Viruses.

I've Listed The Name, Download Link And Detection Rate To Make

Your Life Easier.

Avira AntiVir PersonalEdition Classic:

http://free-av.com/

94.26% Detection rate

avast! Home Edition:

http://avast.com/eng/download-avast-home...