One thing I’ve notice with avast! Internet Security ( AIS5 and AIS6) is that it doesnt turn off the M$ Windows Firewall when you install the program. You have to manually go in and turn the firewall off yourself. The less computer savy probably wouldnt know how to do that.
It also doesnt automatically turn off Windows defender.
Is there a problem running AIS6 with Windows Firewall and WIndows Defender turned on?
No, you can use all with no conflict. However, I see no use in using Win. Defender with Avast since Avast has better detection. You can change Win. Defender to on-demand and only update it when needed.
As for the Windows Firewall (FW), it is up to you if you want to use it along with AIS or not. It is compatible, but do you really need 2 FW’s at the same time? You can use Win. FW as a back up, but it will not enable/disable automatically.
Let me know if you have any additional questions. Thank you.