which is the good antivirus for computer?

Is AVG a free software?

@AnanthuVs yes it's free. I get all the stuff free from here it's good as you can read the editors reviews and users score the program too. Just be careful when downloading as quite often even the free stuff will have extra add ons you need to untick as they don't add any value so go through the user agreements and make sure you're only downloading what you need.