A lot is already been explained about Avast and ZoneAlarm.
If you use the search option on this board and you will find many threads dealing with this.
It also helps if you provide details, like:
What is the exact problem?
What is your OS?
What EXACT version of Avast? (and in this case also ZA version)
What are the settings?
What have you tried sofar to solve it?
etc etc
We can and will try to give help, but we are not mindreaders