Security Essentials is given freely by Microsoft and looks good too but takes time to remove virus. AVG 9.0 Free is also best. I also use it. It's pretty strong one. Try it.
The new version of MSE is due out sometime fairly soon. It's a bit beefier than the current public release. You can check out the Beta.
I recommend Norton 2011, i changed my view of norton completly. Before i would advice anyone to not use it because it was an memory/resource hog. But now it is so good. I use NIS2011, it has also cloud based things in it
Yeah urie is right, it's a real good free av. Has lots of paid features for free. I have a license for the internet security suite.
webroot antivirus+spy sweeper 2011+outpost firewal pro 7.0.4......for me the best combo ever seen....
I am using free Panda cloud antivirus from a while . The system is stable ,no problems ,no viruses , you dont feel it in the background .