OS 1 PC: W7 7100 - connected via LAN OS 2 Laptop: WVista Business - connected via LAN Router1: Netgear DGN2000 Router2: Netgear DG834GT Today I received the dreaded "local area connection doesn't have a valid ip configuration" message when returning to my previously connected PC. The PC was running overnight and did a scheduled scan using Windows Security Essentials at around the time that the error occurred (I was able to check logs with my ISP to confirm what time my connection died.) To resolve the problem I immediately tried to login to the router (tried using 2 different browsers), with no effect. Thereafter tried: 1) Physically rebooting the router 2) Disabling/enabling the LAN adapter 3) Uninstalling/re-installing the LAN adapter 3) Rolling back/ updating LAN adapter drivers 4) Changing CAT5 cables 5) System restore .... all with no result. So I phsically disconnected the PC from the router and fired up my laptop, which is also connected via CAT5. With the PC disconnected and only the laptop plugged in, the router was able to get online perfectly and I was able to login etc. Subsequentlly plugging in the PC results in the "Local area connection doesn't have a valid ip configuration" message, or the PC indicates that it is connected, but I am unable to get online or login to the router. After much frustration I pulled out my old router, connected everything up (PC and laptop) and everything is working fine on both machines. Question: Why can the W7 PC not connect to the router or get online, while the laptop can? If router 1 works fine just with the laptop connected, and router 2 works fine with laptop and pc connected what is happening between the PC and router 1 that is causing the problem? I have also done some basic searching around this problem but any answers I find (such as disabling Bonjour DNS Responder Service, found here: http://social.technet.microsoft.com/Forums/en-US/w7itpronetworking/thread/2c0af923-24bb-4de2-95a7-9a9d4f64a8b0) have not helped. Any advice sincerely appreciated.

Hi, Please also update the firmware for DGN2000 via the following page: DGN2000 Firmware Version 1.3.10NA (for North America users only) DGN2000 Firmware Version 1.1.8.0 (for users outside North America) Please Note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information. If the issue persists, please also run “ipconfig /all” on both the laptop and the PC to check if there are any different or incorrect configurations. Thanks.Nicholas Li - MSFT

I have the same problem!I had two laptops connected to a netgear DG834GT router via wifi. An xbox 360 connected via CAT 5 and two iphones which always recieved wifi from the same router , no problem.I purchased a new computer with windows 7 and since keep getting an IP conflict with the other laptop.The iphones state they are connected to our SSID however they are actually on 3G most of the time.If one of the iphones receives wifi then the other one wont.DHCP is enabled.I have downloaded the latest firmware for the router but feel it made it worse therefore reverted back to the original firmware.I need to constantly reset the router and eventually I get on line.To get on line this time I needed to reset the router and then turn the wireless on as it was not recognising the CAT 5 connection between the router and PC (Recieved the message "Local Area Network does not have a valid IP Connection"HelpVery frustating.Ive run "ipconfig /all" but find nothing untoward.

Try using a static ip

I have the same problem! I had two laptops connected to a netgear DG834GT router via wifi. An xbox 360 connected via CAT 5 and two iphones which always recieved wifi from the same router , no problem. I purchased a new computer with windows 7 and since keep getting an IP conflict with the other laptop. The iphones state they are connected to our SSID however they are actually on 3G most of the time. If one of the iphones receives wifi then the other one wont. DHCP is enabled. I have downloaded the latest firmware for the router but feel it made it worse therefore reverted back to the original firmware. I need to constantly reset the router and eventually I get on line. To get on line this time I needed to reset the router and then turn the wireless on as it was not recognising the CAT 5 connection between the router and PC (Recieved the message "Local Area Network does not have a valid IP Connection" Help Very frustating. Ive run "ipconfig /all" but find nothing untoward. OP here. My problem remains unresolved on the DGN 2000 BUT, I have an old DGN834GT which I am using instead, without any problems at all. I have tried contacting, Microsoft, Netgear and my ISP, all without success. Since my original post I have reinstalled W7 (clean install of W7 Pro, no upgrades or user settings transferred) and the problem still exists on the DGN 2000, while the DGN834GT works perfectly. I have tried upgrading and then rolling back the firmware on the DGN2000 with no success. I am totally mystified by this problem and would really like to know what is going on, and what caused the problem in the first place.