Which is the best Antivirus software ??

I think AVG free is your best bet if you want a free antivirus program. I have tried most of the well known programs (free and paying) and I must say AVG free doesn't do a bad job, definitively since it's a free version. Kaspersky Antivirus Suite is what I use myself. It's paying, but well worth it. Never had ANY problem at all with it. Hope this helps.

One of my friends suggested me to go for Avira. It is working fine for me. It is up to you to update it regularly for better safety. Also, you can buy online any of these antivirus programs like Norton, AVG, McAfee as these are good antiviruses. One of my brothers who is working as an IT professional recommended McAfee as it is very reliable. Hope my discussion helped you. Have a nice day.

the Kaspersky suite is the best for me. Never had a single problem, ever. I've tried AVG, AVAST, Nod, (freaking) Norton and one more.. I forget. But all of them have let through one or another virus. Kaspersky didn't :)