Virus guard

You can visit www.free-av.com. You can download Avira Antivirus Classic Free Edition. It's very light on resources. I can say that since using this one, I never had problems at all and I am very satisfied with this antivirus. You can update this regularly within your scheduled time. It offers online guard which is very important especially when you are regularly surfing the internet. That's it. Hope this would help.

I have Avira antivir and I think is the best free antivirus.