Unidentified Network, No Internet on Vista PC, No connection to router

I have a home office wireless/wired network. Linksys Router connected to SuddenLink's cable modem.
I am writing from my laptop which has internet wirelessly & wired - I checked both.
I have a Mac attached to the same network. I have internet there as well.
My new Vista 64bit Home Premium machine that I got in July has worked fine and I haven't had any networking issues with it. I plugged the cable in and it was ready to go... remarkably easy.

Now, as of 2 days ago, my Vista machine has no internet, and I am connected to a public, "unidentified network" with limited and local access. Very limited because, in addition to losing the Internet, I cannot see my other computers anymore either.

Troubleshooting I have done:
* I have taken wired connections from the laptop/Mac, known to be working, and plugged them in the Vista machine. Not the cable.
* I uninstalled the driver for the NIC card. When restarted, it detected the adapter and reinstalled the drivers. It says it's working properly. Not the NIC card.
* I have unplugged both the router and the modem and even reset the router and reconfigured.
* I restored to the last system checkpoint before the issue occurred - which incidentally was before some Windows update was installed (hmm...)
* I did a netsh int ip reset and a netsh winsock reset , restarted. Nothing.

With Autoconfiguration enabled in IPv4 (and IPv6 not yet disabled):
* I pinged 127.0.0.1 with success. I can ping the auto IPv4 address 169.254.247.64 with success. I get error code 1231 with 192.168.1.1 (router) .
* When I ipconfig it still shows an auto configuration for IPv4 at 169.254.247.64 and a subnet mask of 255.255.0.0 and no gateway. I did a release and a renew. Same thing. I check the device manager & it still has my manual entries. Incidentally, I had made the change AGAIN to “private” vs. “public” for my unidentified, local, limited network. Nothing. So I restart. I'm back where I started: I’m “public” with the same autoconfiguration numbers and in the device manager my IPv4 is again set on Obtain Automatically versus the manual entries I had saved. Every time I reset the network to "private", it resets itself back to public after a restart.

SO - I disable autoconfig & enter the DNS entries myself: 192.168.1.105, 255.255.255.0, 192.168.1.1 respectively.
And - I have - at this point - completely disabled IPv6 through registry changes per http://support.microsoft.com/kb/299357 and http://support.microsoft.com/default.aspx/kb/928233. I no longer get the Tunneling entries in my ipconfig listing either.

* I don't have internet capability on my Vista machine from any of the Safe Modes.
* I disabled IP Helper and my firewall and set WLAN AutoConfig to Automatic.

I'm lost - and I don't know who to call. It doesn't appear to be a hardware problem (Dell or LinkSys) or an internet problem (SuddenLink), but it could be a software problem (Microsoft) to which I have found NO SOLUTION to on the Web.
I need help desperately. Wouldn't you know I took 5 days off to work on a project and this is the 3rd day into it - and I can't do a thing. I need internet access to work with my off-site server and my laptop/Mac can't keep up the file sizes - which is why I got my new system in July in the first place.

Below is the ipconfig, after the latest restart and alterations - still no connection to the unidentified, public (have to set it to private EVERY time after restart), with local access only network.



C:\Windows\system32>ipconfig /all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : Desktop_PC
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Unknown
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : NVIDIA nForce Networking Controller
   Physical Address. . . . . . . . . : 00-24-E8-2E-F8-0B
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 192.168.1.105(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.1.1
   DNS Servers . . . . . . . . . . . : 192.168.1.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Bluetooth Network Connection:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Bluetooth Device (Personal Area Network)
   Physical Address. . . . . . . . . : 00-1E-4C-E6-3B-5C
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

C:\Windows\system32>


Added:
GREAT... I did an even earlier restore, so now I'm back to ground zero.
My ip address is 168.254.159.231
subnet mask 255.255.0.0
Gateway is blank

and the IPv6 & all its tunneling is back.


AND - I'm on the phone with DELL trying to rule out the NIC card again...

OMG! So after 2 hours on the phone with Dell, doing roughly the same thing we did here minus any addressing of the IPv4 & IPv6, they want me to reinstall the operating system... They say that since the LED comes on when I plug the cable into my NIC, that the NIC is functioning correctly and it must be a software issue. It took me 2.5 days to move all my stuff from my old computer to this new one. My entire business is on this PC?! Doesn't that seem extreme for not being able to connect to the internet???? There has to be another solution - c'mon Microsoft! He said if it doesn't work after I backup and reinstall, then they'd have to pluck out the motherboard.
For real? I'm going to try an external NIC card first - I think - before I do all that...






*************NEW UPDATE********************
You are so not going to believe this.... I still haven't received my USB ethernet adaptor, BUT....
I was running a print job on one printer, started one on another, and turned on my heat press, causing me to trip the breaker in my office. I turn everything back on. Restart my Vista machine and boot normally (took my chances w/o safe mode) and LO AND BEHOLD, it prompted me to pick a network (I had managed to create another one through all this mess to no avail) and I can see all my other machines AND I HAVE INTERNET....  Any explanations?

Incidentally, my power does go out from time to time. Can you recommend a good surge protector, maybe one with a battery backup?