I purchased the total security of quick heal . that is real a smart antivirus last year I was using avast and that was ridiculous that some remove my system file also with virus .
and that also cause of window corruption. then my friend suggest me to take total security is little cost then other but it is the gold product.
but never forget to update it every time and also try to install it in other drive then windows.
once you go for will never gonna change your antivirus.
you can also renew it this will less costly then a new one .
if you are going to purchase a antivirus then quick heal may be your smart choice.