What anti virus do you use ??

Windows Defender, AdBlock for Chrome/Firefox and common sense are all that are needed to stay virus free these days.

If you're going to be downloading a load of dodgy software or other things from fileshares or torrents I would recommend using something more robust like Avast! or doing it in a VM and then transferring it out once you know it's clean.
 
I've been using Defender and Malwarebytes Premium when I need ultra protection. I'm really good with my habits, but my the rest of my family members fall for every fake download link and trick there is. The combo between these two has held up to everything that gets thrown at them and without bogging the system down at all. On my computers that I use lightly (and only by me), I use only Defender with a manual scan from Malwarebytes Free periodically.
 
I've been using Defender/Security Essentials for 3-4 years, and it never failed me, but Avast is also a great option. Both are very light in resources, but Avast is very annoying sometimes with notifications.
 
Hi I am using Quick Heal latest version but is not working with windows defender even windows defender is off. what is the problem I can't recognize. need help
 
I used Avast forever until Windows 10 when I noticed it was bogging things down. Removed it months ago and only use Defender now. Works great and PC runs much better. It's not an old PC either, it's an i7 @ 4Ghz, so Avast was really killing it.