Well - I have been trying out all the free antivirus programs on various computers and I have a few new recommendations:
Avira Antivir - one of the best in my experience. Works without slowing your machine and doesn't nag about upgrades or offers.
http://www.free-av.com/en/trialpay_download/1/avira_antivir_personal__free_antivirus.html
Avast Antivirus - I have seen this one catch viruses on two of my personal computers and one client computer - but not good for older machines or if you have DSL internet - the update at startup takes a lot of system resources and can be annoying to wait for it to finish.
http://www.avast.com/eng/download-avast-home.html
Lavasoft Adaware - essential for modern computing on the internet. Get it, run it and watch it find all the nasty stuff that is on your computer. It is a big download and takes a while to run, but is worth it.
http://download.cnet.com/Ad-Aware-Anniversary-Edition/3000-8022_4-10045910.html?part=dl-ad-aware&subj=dl&tag=top5
And the biggie - MalwareBytes Antimalware -If your machine is acting weird this is the first thing to try - it finds all the nasties.
http://download.cnet.com/Malwarebytes-Anti-Malware/3000-8022_4-10804572.html?part=dl-10804572&subj=dl&tag=button
