Hello

2 hours ago, my laptop was working just fine. Windows then decided to install some automatic updates when I went to shut down. After shutting down and powering back up, my laptop's internet was shot - I cannot connect to any external sites, and cannot even connect to the router. I've tried the usual: restart, repair, release/renew, wired and wireless, etc.

Basically, wirelessly, I have "Excellent" connection strength; wired I'm connected just fine (note: I disable wireless when wired in and vice-versa, I'm not trying to connect two ways on one machine at the same time). From the command prompt, when I type "ping 192.168.1.1", trying to ping the router, it sends 4 packets, all are received. When I type "ping 192.168.1.5", trying to ping the desktop computer I'm currently typing on, it sends 4 packets, all are received. When I try to go to 192.168.1.1 in Firefox or IE6, both time out. From this desktop computer, I can log into the router. From the router, when I try to ping 192.168.1.6, which is the failing laptop, it sends 4 packets, none are received. When I type "ping 192.168.1.6" from the desktop's command prompt, 4 packets are sent, none are received.

Currently, the laptop is wired in, and under Local Area Connection Status, in Activity, it claims to have sent 247 packets and received 112. It claims to be receiving packets, but received is always much lower (since this problem arose, that is).

I have tried System Restore, I have tried restarting in safe mode, I've tried wired and wireless. Wired or wireless, the laptop connects to the router, is assigned a valid ip address, shows valid stats under the "ipconfig /all" command in prompt. The laptop claims to be able to send packets to the router and to another computer on the network, but neither the router nor the other computer can send packets to the laptop, so it seems the laptop can send packets but cannot receive them. The system was working fine 2 hours ago, able to connect to the internet, log into the router, etc. The only change I can think of is that I told the laptop to shut down, it said windows had some updates to install, I let them install, and upon starting back up the internet was shot.

I would greatly appreciate any suggestions anyone might have. If more information is required, please let me know (though, it might take me a while to reply, as with the laptop being a stand alone machine for the time being, I can't run something then copy/paste it, I'll have to transcribe results onto this desktop computer before posting). Thanks for reading through this.

Well, I figured it out - I remembered that the Add/Remove Programs list in the Control Panel shows all the updates that Windows installs. Turns out what messed me up was KB951748, a security update released on July 8 that does something to "Tcpip.sys" and to "Dnsapi.dll", which I'm guessing is what messed with my system, since I'm now back online and responding from the previously busted laptop after uninstalling this update.

For more info:
MS08-037: Description of the security update for DNS in Windows Server 2003, in Windows XP, and in Windows 2000 Server (client side): July 8, 2008


My suggestion, if Windows offers to install this update, DON'T.

Check your Firewall settings. You may have been able to disable the Firewall on your computer, reconnect and then enable the firewall again.

The next time you run Windows updates, it may recognize that you have removed the update. Watch for it again and good luck.

Our own MS WSUS servers keep our computers up to date and this update has been installed on about 1000 machines so far without incident.

I had the same problem and I am now trying to uninstall the recent window update (the one you have mentioned). I hope it'll work!
Thank you though, for your posting. I was going to just buy a new computer! :)
Will let you know if it works!!
Another question though, without the new update from window, is it going to affect the computer in any ways?
THANKS A MILLION!

Hurray! It works!! My gosh! Thank you thank you thank you!! Can't thank you enough fictionality7!!

@sidneyleee, I can't make any promises, but it looks like chuckhole was right - a few days after my initial posting, zonealarm released an update specifically geared at fixing issues with KB951748. I've downloaded zonealarm's update, but have not installed it yet, and I'm not going to go out of my way to reinstall KB951748, but it's entirely possible that, if you're running zonealarm, their latest update (I say latest because it's the latest that zonealarm automatically tried to get, but it was probably released around July 13th or 14th, so it may no longer be the "latest") *may* fix the issues that sidneyleee and I experienced

@chuckhole, like I said, I haven't verified that zonealarm's update will fix the issue I had, but the very fact that they released an update to deal specifically with the Microsoft update that gave me issues leads me to believe that it *was* my firewall causing conflicts, just as you thought, so amazing job with the diagnosis as it seems to have been spot on

You get a thumbs up from kirby (o '')b

I appreciate the kind words.

Keep it up. Even if your research is still not yet complete, it has already made Sidneylee happy and as a precaution, I have passed your information on to my colleagues who are running Zone Alarm.

My computer sending packets but can't receive
Here is the situation... I can use my computer for few hours and I can receive packets but after that few hours my computer stop receiving packets...
I tried all ipconfig/release-/renew... can you help me... I thnk its on the updates that I updated to my computer... how can I uninstall the updates?.
I don't know where to look this updates don't know where can I uninstall it help please..

Follow up... but I can receive packets for a short period maybe 5sec if I repair my Local Area Connection... then its stop again...