There is no conflict with the ZA free version only if you have the pro version and use the privacy settings on high.
http://www.avast.com/eng/webshield_issues.html- ZONE ALARM - AVAST Web Shield compatibility dialogue - Install/Update Question - YES or NO
If you are using ZoneAlarm Free you should click NO, because privacy features are not present in ZoneAlarm Free this will not turn off web shield transparent mode proxy.
Use a text editor and edit the avast4.ini file, the default installation location is C:\Program Files\Alwil Software\Avast4\DATA\avast4.ini (I would advise you copy avast4.ini before editing it, just in case).
Locate the line containing ZoneAlarmCompatibility= and delete that line. Save the edited avast4.ini file.
If you are using ZoneAlarm Pro and Privacy Control in ZoneAlarm is set to High and if you click YES in avast compatibility dialogue box the transparent mode proxy in web shield will be turned off you have to manually configure browser to access internet. To manually configure your browser watch instructional video
For IE - broadband users: -
Tutorial - Web Shield Proxy Set-up for IEFor IE - dialup users -
Tutorial - Web Shield Proxy Set-up for IE (Dial-up)For Firefox users -
Tutorial - Web Shield Proxy Set-up for Firefoxavast isn't a firewall so I don't know where WSC is getting that from. It hasn't reported either web shield or network shield as a firewall on my system. So another hiccup on WSC by the look of it.