I run Kaspersky as my anti-virus. You might go to their site - kaspersky.com
At the very top of their webpage are two small clicky links - 'Free antivirus scan' and also 'Free Trials'. Run the scan and then download a free 30-day trial of one of their products. If, after 30 days, you like it, you can buy at the site (not cheap), thru Amazon (cheap) or Costco also carries it. Been running it for about 2 years now.