Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Users\Beau>ipconfig/all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : Beau-PC
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : NVIDIA nForce Networking Controller
   Physical Address. . . . . . . . . : 00-1A-A0-68-44-B6
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::7de8:5457:63d1:c241%9(Preferred)
   IPv4 Address. . . . . . . . . . . : 12.217.1.37(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.248.0
   Lease Obtained. . . . . . . . . . : Tuesday, March 25, 2008 7:26:09 PM
   Lease Expires . . . . . . . . . . : Friday, March 28, 2008 4:56:01 PM
   Default Gateway . . . . . . . . . : 12.217.0.1
   DHCP Server . . . . . . . . . . . : 12.207.234.13
   DNS Servers . . . . . . . . . . . : 204.127.203.135
                                       216.148.225.135
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter Local Area Connection* 6:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 02-00-54-55-4E-01
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 7:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 12:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft 6to4 Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2002:cd9:125::cd9:125(Preferred)
   Default Gateway . . . . . . . . . : 2002:c058:6301::c058:6301
   DNS Servers . . . . . . . . . . . : 204.127.203.135
                                       216.148.225.135
   NetBIOS over Tcpip. . . . . . . . : Disabled

C:\Users\Beau>

To help troubleshoot this problem, on the computer with the problem, go to Start > Run and type cmd then click OK. In the command prompt window that opens, type ipconfig /all then hit the enter key. Write down the output from this command or select it and save it to a txt file, then copy this output into a reply to this message.

Steve

I don't see any problems in your ipconfig output.  Let's try to narrow the problem.  First, go the command prompt window again and type ipoconfig /flushdns.  Then check the internet connection.  If it still doesn't work, we need to troubleshoot further.  Try booting to Safe Mode with Network Support and see if it works.   Report back what you find.

Steve

I exchanged the router, had the same problem, fixed it again, had the same problem, fixed it again.  Here is another thread I started.  Not sure what is going on, but I think the 360 and router have difficulty communicating.  The router assigned its IP address to the 360 as the DNS and now it works. 

http://www.dellcommunity.com/supportforums/board/message?board.id=netwkint&thread.id=28705