I'm currently running Windows Defender and MalwareBytes Premium.
In the end though, all you really need is Windows Defender, as long as you know your way around the internet.
If you dig yourself into an unknown website or open up strange emails or accept files from unknown sources, you are sure to get your PC damaged.
But if you play it safe, scan everything before hand (with like VirusTotal and such), then you should be just fine.
Of course, having add-ons and such like Ghostery, Adblock Plus, Adguard, and so forth are also handy as a support unit.
I've been hearing that Linux is virus-proof, and user friendly and even works on old hardware! That's why I've been using Ubuntu MATE on my old laptop. But since I need particular software like Photoshop, I need to use a Mac and Windows laptop. (I am aware that I can just use GIMP, but since I'm more familiar on Photoshop than GIMP, I leaned slightly towards Windows, and I can't even buy a Mac since I have limited funds :p)
Anyways, what do you guys think of Avira (free version)?
Linux isn't "virus free", just very few people actually use Linux, so no real reason for hackers and such to target them. Of course, Linux does have trojans and so forth, but these are a rare bunch.
As for Avira, it is about as useful as Windows Defender, this also applies to EVERY single antivirus program which is LEGITIMATE but "free" (and even paid ones as well). In the end, all of them are pretty equal in status, but some of them are a tad bit behind the rest of the group.
AVG is a mockery of an antivirus program, indeed it is good, but it isn't as good as Sophos or Avira.
Malwarebytes is an amazing product, but unless you have it paid (or cracked/hacked), you're missing out on 24/7 protection. Otherwise, it is about as productive as Avira or Sophos.
Of course, there are other honorable mentions and acceptable programs to use as well, such as:
HerdProtect
ESET
TrendMicro
Panda Security
Bullguard
...and so on and so forth. All of these programs are in some way pretty good and yet, also pretty bad. Most (if not all antivirus/antimalware programs) have some kind of "flaw" that the other antivirus/antimalware programs may not have.
As said before, it all comes down to how you approach the internet. As long as you're not browsing dangerous websites, accepting unknown files and links, and exploring strange content, you should be just fine with generic antivirus and anti-malware programs like Windows Defender or even AVG.