Do you need Windows Firewall with Avast?
Running only a firewall or only antivirus application isn't enough if you're concerned with protecting your data. Microsoft now builds in a firewall with its Windows operating system, which does work well with antivirus solutions such as Avast Free.
Should I turn off Windows Defender if I have Avast?
Regardless of which third party (i.e., not Microsoft) anti virus application you choose it will always turn Windows Defender off to prevent conflicts. In answer to your question "will it cause a conflict between defender and avast running simultaneously" the answer is Yes it will.
Is it better to have firewall on or off?
Newer firewalls on both PC and Macs are checking each packet in micro-seconds, so they don't have much drag on speed or system resources. Turning them off won't give you any real benefit, so it's better to leave them on and have that extra layer of protection.
Should I turn off firewall for gaming?
Turning off the Windows firewall will let you play the game, but this step potentially exposes your computer to unauthorized access. Another option is to allow the program through the firewall. Doing so not only allows you to play the online game but it also maintains protection from online threats.
Is turning off your firewall bad?
Whether it is even realistically possible for ISP's to block most Internet attacks, other than much (but certainly not all) of spam, is highly questionable. Whether they actually are effective at blocking most Internet-based attacks is absolutely not questioned, and the answer is absolutely: no.