I've not really used any AV for the last decade. If I think I might have something, I'll install Malware Bytes just long enough to do a scan and then uninstall it. But after the recent horrific bug found in every single version of Symantec AV, I think it's safe to safe what has already been true for a while. Antivirus is dead. These days they don't actually do anything but slow your system down and make it less secure. What's more sad is that most major AV companies have Android versions of AV, despite the fact that they can't actually protect your phone, detect a virus, or clean it if you had one. For that they'd need root access, which you could only give it if you had rooted your phone. None of them mention that. Also, again proving they make you less secure, if they could achieve root access, then you can bet that every virus maker would target those apps as a new way to attack phones.
The best method I've found for protecting a computer is the two or three partition method. Keep Windows on one partition, and your data and applications on another one (or two). That way when your system inevitably gets screwed up, just format and reinstall Windows, then reinstall your applications using the settings saved on the other drive. Also, be sure to keep copies of driver/application installs. I've followed this method and it's never steered me wrong.
Also, on a side note, if you're planning on upgrading to Windows 10, grab this tool and make an installable USB drive or DVD. After you upgrade, format and do a fresh Win 10 install. Windows upgrade has never worked, and don't let anyone tell you otherwise. It's only a matter of time before an upgraded system starts to break down in weird ways nobody can explain or fix.