Free Downloads
The most requested recommended free downloads are free virus scanners, free firewalls and free spyware removers. There are a lot more, but these are among the best.
Free Virus Scanners
AVG (New version 8) Highly recommended by users.
Avast Also highly recommended by users.
Antivir
Microsoft Security Essentials I am using this on two computers!
Free Firewalls
Comodo Here is what the site has to say "It's Free. Forever. No Catch. No Kidding." Highly recommended!
ZoneAlarm Just click on the ZoneAlarm (free) listed under Direct Links and the download will start. Zone Labs keeps changing the link for the free version, if the link doesn't show the free version, use the search function and input 'free Zone Alarm.
Since this page was uploaded just a few days ago, they have already changed the link. So look at the comparison page which also has a link for the free download.
Free Spyware Removers
Just go to Spyware Removal Tools and get them all! Be sure to update each before running!