LAN is working but Internet is not working

Hello Everyone,

Problem: I am able to access the computers, and the printers in my network,
but am unable to browse any website.
Error received: Internet Explorer Cannot display the webpage

Network Setup: I am on a Peer-to-Peer Network with no firewall on the
gateway. The Router is connected to the Network Switch, and my computer is
also connected o the network switch (sae or different switch, and the network
switches are interconnected).
Information about my Computer: I am running Windows XP Service Pack 3, with
Internet Explorer 8. I am also running Symantec Endpoint Protection on my
system with Windows Firewall disabled.
Notes: 1. The other computers in the Network are working fine.
2. The Ping to the default gateway (192.168.1.1), 127.0.0.1, localhost, and
other computers on the network is successful.

STEPS taken by me:-
Step I:
1. Ran - "Diagnose Connection Problems" from inside Internet Explorer 8
2. Error received: "Windows has detected a problem with the Winsock provider
catalog on this computer.........Would you like Windows to reset the catalog
to the default configuration?"...
3. Clicked Next to reset the Winsock
4. Restarted the computer
5. Not solved

Step II:
1. Followed the following more ways to reset the winsock:
a. netsh winsock reset (Command Prompt)
b. Microsoft Fixit 50203
c. WinsockXPFix.exe utility by Option^Explicit Software Solutions
2. Restarted in all the steps
3. Not Solved

Step III:
1. Ran all the different netdiag tests, which passed successfully.
2. Not Solved

Step IV:
1. System Restore
2. Not Solved

Step V:
1. Deleted the Registry Keys 'Winsock' and 'Winsock2'.
2. Restarted the system
3. Installed TCP/IP
4. Not Solved

Step VI:
1. Ran LSPFix.exe from Cexx.org
2. "No Problems Found"
3. Restarted the system
4. Still not solved

Request for your Help!
Regards,
Yagyesh