Open Source Anti Virus

It’s frustrating. I had downloaded the trial version of Microsoft’s onecare, the anti-virus, when I purchased my laptop. I wanted to stick with Microsoft. So today, I thought of converting the free to paid version. But Activate clicks from the client lead me nowhere. Wasted three hours just to figure out how to make a purchase. Annoying windows live website.

I call it quits.

I am downloading a open source anti-virus. Did you know there is one. Calmwin. Dowload it here. It’s completely free.
Google Pack also has Norton anti-virus, but I read that it’s free for only first six months.

Which anti virus do you use ?