There are several of antivirus are available in market and you might confused which one to use and which one to not, so please take my advice seriously, chose antivirus according to youre laptop capacity.
sometime youre laptop cant run heavy software then keep in mind which will shuit you, just like nothrn is heavy antivirus and need high ram and processor then its work awesome.
but quick heal are made of every one because its lite and just keep updated youre good to go, even you can scan youre phone with quick heal, this is why I love it.
some of antivirus comes free like avast and k7 thier crack version are available everywhere so please careful to buying, they are useless antivirus.