I require a free anti virus software

Hi there,
I have been using Norton anti virus software for quite sometime now, and have recently upgraded to their most recent version. But the thing is, the Norton antivirus is not that much effective any more as it was around a decade ago.
I am open to any other solution, be it Norton's higher caliber security suite or do you recommend jumping ship to another anti virus software, and if so which one?
Thank you.
