Comodo Firewall/Defense + and Vipre Antivirus

I’m searching for a good antivirus for my Windows 7 laptop. Nosing around, I can coming across compatibility issues with Defense + and Vipre Antivirus.

What can be done about this? I don’t want to lose Comodo. Would simply turning Defense + off prevent problems? Can Defense + be deleted without losing or effecting Firewall?

Or is this even an issue anymore, as bug fixes may have figure things out?

Are there any other compatibility issues with other antiviruses I should be aware of?

Perhaps you could explain the problems you are having?

No problems - I haven’t downloaded an antivirus yet. It’s just a concern I have after noticing previous compatibility issues others where having between Vipre Antivirus and Comodo (particularly with Defense +).

I just want to make sure before I pay for an antivirus product.