I'm helping the in-laws out here.  A few days ago they discovered their PC (XP Home) wouldn't connect to the internet.  They called Charter Communications (broadband provider) and went through a number of troubleshooting steps with the phone tech.  He determined it had to do with the Defender Pro Plus firewall software installed, but he couldn't figure out how to fix it.

 

Tonight I did a clean install of XP and didn't load any firewall software.  Still can't get an internet connection.  I called Charter Comm myself and went through troubleshooting with the phone tech.  We determined all settings were okay, XP firewall was disabled, PC was recognizing the proper IP Address.  But no network traffic was passing through.  He did a remote check of the cable modem.  He had me try to ping yahoo.com, to no avail.

 

He said something is blocking network traffic, most likely a firewall, but there isn't one installed on the PC anymore.  Why didn't a clean install of XP work?  Could there be a registry bug or virus that remained?

 

I'm stuck and would appreciate any assistance.