VPN conflict with Avast Internet Security firewall setting.

[size=12pt][size=14pt][size=12pt]Hello.
I have to disable the Avast firewall in the Windows 7.0 Firewall control panel in order a specific non-Avast VPN software works properly.
Therefore, I should be grateful if you explain in detail the correct procedure to change the Avast Internet Security firewall setting to avoid IP and DNS leaks and further conflicts.
Cheers.[/size][/size][/size]

https://www.avast.com/en-eu/faq.php?article=AVKB25