For years, I use Kaspersky Internet Security. So far I had on any PC using this antivirus protection problems with any viruses or Trojans. The product is more than worth your money if you stay with it spared much trouble. Because of problems with Adobe Flash Player, I turned to Kaspersky protection for download and installation recently. Prompt I have then is so much crap on the PC that I immediately run to restore an Acronis backup of drive C (luckily only 3 days old).