Applications cannot access internet

[canoe]

Sorry for the long list but I wanted to avoid "to and fro"

1. three computers are on a LAN thru a DLink DI640 router via ethernet
2. All computers on the LAN can access all shared resources
3. All computers can ping successfully on each other
4. All computers which I have allowed internet access can ping successfully on google.ca
5. #1 computer can access the internet with applications:
Firefox3.0.4, IExpl7.0.5730.11, Outlook Exp6.00.2900.5512
6. #2 computer has been blocked from internet access by me in the
router
7. #3 computer cannot access the internet with those same applications
8. #3 OS is WinXP Home
9. #3 Free ZoneAlarm firewall and AVAST antivirus are installed
10. #3 AVAST automatic update gives message "can't update"
11. #3 disabling firewall & antivirus has no effect
12. #3 Firefox with www.google.ca address eventually gives message "Network Timeout"
13. #3 has two Network Interface Cards and I have tried both
14. #3 clicking on MyNetworkPlaces > View Network Connections shows three categories: "Broadband", "Internet Gateway" & "LAN or
High-Speed Internet"
15. #3 clicking on Internet Gateway > Internet Connection shows packets sent & received under Internet Gateway are static while under My
Computer are continually increasing
16. #3 clicking on Broadband > Sympatico shows "Disconnected"
(before the Router was installed, #3 was connected by ethernet to the modem with ISP [Sympatico] supplied the software)
17. #3 clicking on Sympatico opens a window "Connect Sympatico"
with User name already entered & Password "click to change"
18. #3 clicking on Properties > Networking shows:
Type of connection - PPPoE
TCP/IP and QoS Packet Scheduler are ticked
19. #3 clicking on Connect opens a window "Connecting Sympatico - connecting thru WAN Miniport (PPPoE)" - eventually gives error 678
"Remote computer did not respond..."
20. #3 physically connecting #3 to the modem (via ethernet cable) instead
of the router and again clicking on Sympatico shows "verifying Name &
password" and then shows "connected to Sympatico"
21. #3 Firefox can now connect to Google.com, IExpl & OutlookExp can
also connect
22. #3 clicking on MyNetworkPlaces > View Network Connections now shows only Broadband and High-Speed Internet - Internet Gateway is
gone
23. #3 If I disconnect from Sympatico - click back to MyNetworkPlaces & click forward again to ViewNetworkConnections - Internet Gateway is
still gone
24. #3 when this problem first appeared I noticed some kind of message about IP conflict - no other computers were powered up at the time.
25. #3 I did a System Restore to a date before this problem appeared without any improvement

[BiGMaCHiNe]

Are you saying that "Internet Gateway" is not working? (correct me if I am wrong)

[canoe]

BiGMaCHiNe

I just meant that the heading "Internet Gateway" had vanished from that window.

The problem has since been corrected. I suspect the Restore did it.

Although I had rebooted yesterday after the Restore, I opened a Limited account rather than the Admin account. When I booted up and opened the Admin account today I got a message that the Restore was complete and everything now works.

[canoe]

The problem seems to be catching.

I have exactly the same problem now on computer #1 (Win 2000) but #3 has been OK since my last post.

I tried a registry restore on #1 which had no effect. There doesn't seem to be much choice with Win 2000 restore.

Any suggestions?

[yuppicide]

Hello,
Internet gateway problem causes lot of difference what we understood than in the existence but I will suggest you the following link,There's a good set of tips here:
http://practicallynetworked.com/sharing/ics/ics.htm

I'm sure I looked at it a few weeks ago and saw advice on the internet gateway icon but I couldn't quickly find it this time. Maybe if you have a good scout around you might find what you need.