Avast best free antivirus
After using numerous free antivirus programs I recently had the opportunity to research different programs, and the Avast was the leader. I also recently, had the opportunity to place the Microsoft Security Essentials on both of my computers, a XP, and a Vista. Windows Security Essential will not play well with the Windows Defender, on either the Vista, or the XP. Although, they are Microsoft programs, I was surprised that they had a conflict. If two children can not play together, you will have to separate them.
So, I installed Avast, and ran the Windows Defender together with each other. The review I watched indicated that Avast was no more of a resource hog, than, any of them. And, all of the free programs are actually better than the paid ones. Meaning, they use less CPU.