Here's the truth everyone - just use free: Avast, Avira, spybot s&d, superantispyware and one paid program: lifetime Malwarebytes Anti-malware. ($10 on sale) Perform frequent scans with all, auto if possible. By using all of these programs, you can catch viruses/malware that one or more of them may miss.
Finally, restore entire system to a perfect working and clean state via clone from a backup every 3-6 months, if this scenario is realistic for you.
Another tip, don't ever go to any porn site on a PC. Use a Roku for that. (Nowhere porn, etc) Otherwise, keep "clean" movie files available.