RE: abhi95sinha's Config - Need a good AV
Avira Free Edition is also fabulous if you are astute and fairly skilled. I always remember it being easy to live with.
You could go outside the box like me; Threatfire AV Level 5:
http://download.cnet.com/ThreatFire-AntiVirus-Free-Edition/3000-2239_4-10726873.html
You will be whitelisting for a while, but once you get it set up (similar to training a firewall) you can shut it down when you run certain programs, out of the blue, that you know are legit. Just right click the toolbar icon and select "suspend". I do this when I use certain programs that I won't be using again, or for quite a while.
Add Sandboxie for unfamiliar sites and random search engine surfing.