Since you have Comodo, you may want to try Avira free for the AV portion;
@hjlbx (A-number-one Comodo fan) likes that combo, so it's probably without conflict and an effective solution.
I like Comodo because it works for me, but I wouldn't rate myself as a "Fanboy" - although it might appear at times that I am. To the contrary, at times I am disappointed, befuddled and frustrated with both Comodo products and corporate. I will be the very first to state CIS can be a handful and has problems.
That being said, Avira Free antivirus and Comodo can work together - but Avira can tax the network since it is cloud-based. Avira is nothing but a scanner with some advanced tweaks that probably add little, if any, additional protections.
Unless a person is a click-download-happy-high-risk user I find that most AVs are sufficient for typical, daily use. I'm not saying they are perfect, but they do generally provide a base-line system security above that of Windows Defender.
The natural inclination for most users is to layer their system to the N-th degree... you know, "Impenetrable-Fortress-Syndrome." Anyone who spends time at IT security sites knows exactly what I am talking about.
My ideal security config:
1. Anti-executable
2. Virtualization
3. Outbound Firewall Notifications
This can be achieved in two ways:
A. Comodo Internet Security - properly configured
or
B.
1. AppGuard with NoVirusThanks Exe Radar Pro
2. Shadow Defender (and\or Sandboxie}
3. BiniSoft's WIndows Firewall Control
I would like to see\find a more robust firewall solution that Windows Firewall since its self-protection is quite weak... hence the definite need of an anti-executable.
Option (B) is both light on CPU and RAM usage... but at the same time, on my specific system, so is Comodo.
More importantly, the softs in option (B) are very dependable and reliable (except Sandboxie - in my experience - on my specific system).
If I only had the choice to have one security-related soft then it would be Shadow Defender...