Vista "local access only" nightmare

This seems to be a widespread problem and it is really driving me totally nuts.

I have a brand new PC, together with a faithful wireless router, and to cut a long story short ended up with a successful internet connection for a couple of weeks via my usb wireless network adaptor. Then a week ago, for reasons unclear (but hopefully irrelevant given subsequent system recovery), the internet connection stopped and reverted to local access only.

Initially resetting the router worked but not for long.

Then I tried various system restores and netsh commands to rebuild the tcp stack and repair winsock (if they were ever corrupted). Finally I tried the DhcpConnDisableBcastFlagToggle registry entry and that seemed to work, but again not for long.

Since then nothing at all has managed to get away from just local access.

The wireless signal is very strong.

I have restored the vista image from the recovery disk and installed only the precise driver that worked during the period of successful internet connectivity.

I have disabled IPv6, added the registry entry above, all to no avail.

I can access my wireless router itself via my vista machine, and can ping my xp laptop (which is connected just fine). My iphone connects, my friend's xp laptop connects and another friend's mac book connects.

The only thing that doesn't connect is this vista pc and the only thing that is on is vista 64 fresh from recovery and the driver from October 2008 that worked before.

Any help would be gratefully appreciated .........

From a clean restore of the vista image I tried these steps from another discussion forum:

"I ALWAYS do the following steps to solve this problem in many computers, and it never fails:

1) Power Settings to High Performance
2) HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\[guid]\DhcpConnForceBroadcastFlag 0 wireless interface
3) HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\[guid]\ArpRetryCount 0
4) HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip6\Parameters\DisabledComponents 255 (hex)
5) Start -> Run -> services.msc -> Disable "IP Helper"
6) Start -> Run -> ncpa.cpl -> Right click ur wireless conection -> Uncheck TCP/IP 6
7) Start -> Run -> cmd ->
netsh interface tcp set global autotuninglevel=disabled
netsh interface tcp set global rss=disabled
netsh interface tcp set global ecncapability=enabled
8) Reboot"

Didn't fix my issue, but the current state of play is that not only can I connect via IE to my wireless router, I can ping my laptop by name, and I can ping google.co.uk using it's ip address rather than the name.

Also I noted that in my laptop's ipconfig /all I had DNS servers other than my router specified, whereas in vista I had my router specified (albeit that the router is set to assigning it automatically from the isp and shows a different value again).

Turns out that I had had a previous issue with my broadband provider which meant my xp laptop and iphone had hardcoded dns servers.
The router still had automatic dns.
Anyway, adding the hardcoded dns servers to my vista connection seems to have resolved the issue. I have no idea why it worked before but not now.

My visitors never hardcoded the dns servers but they were ok.