That's the thing about Zone Alarm Pro, there's ALL sorts of configuration settings you can adjust. If you're having problems with ALL websites, I'd say you probably haven't installed it correctly. Only certain sites will cause problems under the default installation settings, and they can easily be remedied if that was in fact the case.
Since you're saying that ALL sites are causing problems, I'd recommend a full uninstall, then a reinstall. If you still have problems, get a hold of ZoneAlarm's customer support, they're usually pretty helpful...
Hmmm..anything to watch for specifically so that it's done properly since I'm NOT computer literate??