Jan 02

Local Area Connection doesn’t have a valid IP configuration ,please help!

Hello all.

I need some help with my computer.  I don’t know what exactly is wrong, only that the thread title is what it says when I try to diagnose the problem.  I’m experienced with computers, but just need to know what steps to take to fix this.

Tried restarting, tried turning on/off modem.  Everything is plugged in.

BTW using WIRED connection to DSL modem/router.  It is a wireless modem too.  I’m connected to the modem right now through a laptop and Vista.

1 comment

  1. bigtomesz

    My search for the answer to this took me everywhere. I got mine fixed and nobody else seems to have done it this way, so I wanted to pass on this cure in hopes it might save someone a lot of time.

    First of all I live in a Best Western Hotel (not a motel) and they have EXCELLENT tech support. The BW tech support guy unblocked me from wherever he lives at the other end of the phone. He spent a total of about a minute doing this. Here’s what happened and what he did.

    The Problem
    My computer’s wireless and Ethernet adapters were physically blocked from the router. I had an Unknown network and got the dreaded 651 error and the message, “Local area connection doesn’t have a valid IP configuration .”

    How’d that happen?
    I was using an add-on to Firefox to check my bookmarks for dead links. I can’t remember which add-on it was because I reverted to an earlier version of my OS in an attempt to fix it. When it reverted it deleted the add-on. Today when I went to find it again, it is not available. Wonder why??? The kicker to all this is that I was watching my computer when the problem happened. It was like someone flipped a switch turning off my Ethernet adapter. I was on the wired connection (Ethernet) and switched to the wireless with no problems…until I tried to check my dead links again. Again the switch flipped off but for my Wireless adapter. RIGHT IN FRONT OF ME! Then I was really dead in the water. The problem was that the Best Western firewall saw my computer checking my bookmarks. The computer checked more than 300 websites within 1 minute and the firewall thought my computer had a virus. Thinking it had a virus the firewall blocked the physical address of my Ethernet adapter (first) and my wireless adapter (second) from further connections.

    The Fix
    Start by running cmd from the start menu
    Type “ipconfig /all” without the quotes
    Write down the physical address of which ever connection is/are not working. If you are hard wired to your router, then use the Ethernet adapter physical address. If you are running wireless, then use the Wireless LAN adapter. I had to do this for both.
    Go to your router’s firewall and find the physical addresses of the connections.
    Find the physical address(s) of your blocked adapter(s) and unblock it.
    Sorry I can’t be more specific for everyone’s router but that is the general idea. I’m using Win 7 but I don’t think it makes any difference.

    YOUR problem
    If you did not do anything unnatural that a firewall might have picked up as a virus, then you might have an actual virus that your outbound firewall blocked.



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