uninstalled Norton AV, installed Zonealarm, network doesn't work !

Used to have Nortons 2003, which was replaced yesterday by installing Zonealarm ( free version ), now my sons computer can no longer access the internet. Was working flawlessly until the change. We have a dialup connection.

Reason for the change was being infected with spyware/virus, which after a number of hours of work, with info provided on this site to fix was repaired . I've followed the "sticky" as best I can and have installed everything ( I think ) which was required to prevent or detect another attack.

Both machines are running Windows XP Home.
my computer shows the link ( D-Link Air+ ) to be working fine, but feel the access is probably being denied by Zonealarm.
Network Connections shows Wireless Network Enabled.
The Zonealarm shows
D Link airplus DVV and an address entry type internet
WAN (PPP/SLIP)I and an address entry type internet
Rays Lifeline an address with entry type IP Address


As a practising computer dummy, I don'y know what this means.
My son is 12yo and well on my case to sort this out. I'd sure like to keep him happy, he's a good lad.

Hope this is enough to go on, if not, letme know, will try my best to provide requred info.
Please explain anything to me really simply, I'm a newbie to these computers and sure struggle with all this stuff.
Thanks
cheers
richo
PS If I'm asking in the wrong forum, please redirect me.

 

Think I'm at the root of the problem, have reset the Internet Zone Security to medium. This allows my son access to the net.
Will ask in another forum ( software?, spayware/virus? ) on how this new move affects security.
cheers
richo