manojgj :
try avira or avast free with malware bytes..
I'm running Avast Internet Security and I like it. The free Avast antivirus is good as well. It comes with email scanning in it and no nagware dialogs either.
Microsoft Security Essentials is good too.
You can't really go wrong with any of the choices given.
ESET NOD32 isn't free, is it?