Thanks for supplieing the additional information.
I am a bit tired at the moment. And this is not a pratice I do every day (only on initial installs).
Anyways.
After you did all this reboot, go to the command prompt and type netstat -an to check for additional open ports that need to be disabled.
Also type ipconfig /all (like metioned in the other thread) to check you internet configuration.
There is a tutorial here at AO called:
How to Lock Down Your WinXP Box... that will help you out in securing your XP machine.

Cheers
noODle