I use 2 firewalls too, software Zone Alarm and a Netgear FR114P, and have no
problem with ebay especially ;o)
When you say you disabled the firewall for your game playing son. Have you
actually added your son's machine as a DMZ machine or is the router
forwarding ports to his machine depending on the game he's playing? If he's
on DMZ, it's very dangerous as his machine will be treated as if it's
directly connected to the internet without router/firewall. Because he's
also on your network, this can have knockon effects to other users.
Aside from this, is the Netgear configured with default settings or have you
tried adding any rules of your own?
Back to your machine.
If there's no "allow other network users to connect through this computer's
internet connection" option on the advanced tab of the Local Area Connection
properties box, then that shows you dont have internet connection sharing
installed for this network adapter. That's good/correct.
Have you checked your event log (available from Administrative tools\ Event
Viewer)? This may give a better idea of what is happening when you try
disabling ICS/ICF.
Check your running Services from the Administration menu. In the Services
list, there should be an Internet Connection Firewall (ICF) entry.
Mine says Startup type is Manual, Status is not running and LogOn As Local
System.
Is it there? What is its status, startup type and LogOn As? Right click and
select "properties". Try turning it off from in there. Check through all the
tabs and see if anything looks wrong - especially on the dependencies tab.
Compare the values with any other xp machine you have at home.
It does sound as if your PCs network is screwed up.
If your machine were mine, Id start by trying to destroy all the components
for the local area connection eg TCP/IP clients etc. (It used to be easy to
do this with earlier versions of windows, I dont know if its the same for
XP.) then reinstall the network.
You say you tried to do this, what happened?