On two computers, I have Ubuntu 12.04. On one it is exclusively Ubuntu 12.04, and the other I dual boot with Ubuntu 12.04, and Windows XP. On the Ubuntu I have no virus program. And, on Ubuntu I have never caught a virus now for over several years. I had always ran several different free virus programs. I liked all of the free virus programs. They all seem to have a problem with reporting false positives. On the Windows XP I have Microsoft Security Essentials, and on a computer in the back, with Hewlett Packard, dual core, Vista, I have Microsoft Security Essentials, and I like the Microsoft Security Essentials on anything with Microsoft program, e.g., XP, or Vista.