I have a clean install of W7 RC. I also have 2 XP SP3 machines all connected to the same ADSL Modem/router via Ethernet - so no wireless issues. The XP machines work just fine all the time. The W7 machine has an Nvidia chipset. Initially I had intermittent issue with not seeing the internet. I could get to the router and see it's web page but still no 'external' connection. Then I was having intermitent connectivity to the network itself. Really frustrating. I tried the latest Nvidia driver package and things have got worse. Now I can't get onto the network at all. I have DHCP enable on the router with a 10.0.0.x IP range. I have enabled DHCP on the NIC. I used to get something sensible, but when I boot up the W7 machine I now get an IP address of 169.254.203.199 - does anyone have any idea where that came from!!! As I can't get on to the internet I assume this is it buried in the W7 code somewhere - any ideas? Disabling DHCP and fixing the IP address of the adaptor to 10.0.0.x range still doesn't fix the connectivity, but I am very suspicious of the rouge IP address.

That is an address reserved by IANA for host connections when DHCP has not assigned an address. Not rogue, DHCP is not working. Quote from RFC 3330:169.254.0.0/16 - This is the "link local" block. It is allocated for communication between hosts on a single link. Hosts obtain these addresses by auto-configuration, such as when a DHCP server may not be found.Run ipconfig /all from the command prompt to determine the status and work from there. Do the same on the XP machine to get a reference.The problem with troubleshooting is that trouble shoots back.

I suggest you run a packet sniffer such as wireshark and watch for DHCPOFFER UDP packet from your router. Turn off all possible "firewalls" etc, to be sure to allow UDP 67 68. As for "disabling DHCP and fixing the IP..." - does your router configuration allow manually assigned address ? are you within range ? If you still cannot ping outside your room, disable everything but IPv4 on your win7 machine, execute ROUTE PRINT command on both your XP box and Windows 7 and compare.

Hi, Thank you for your posts. 169.#.#.# is a APIPA (Automatic Private IP Addressing) address. Generally, if the system cannot successfully get a valid IP lease from the DHCP server, an APIPA address is used. Therefore, it indicates that the problematic computer was still unable to get a valid IP address. Additionally, I would like to suggest the following: 1. Manually assign IP address, subnet mask, default gateway and the DNS settings to this network adapter referring to your routers settings or the good computes configurations and check if it works. 2. Upgrade the routers firmware. 3. If it is possible, please connect this computer to another network and see how it works. If the issue persists, please also let us know the brand and model of the NIC, we will perform some further researches. Thanks.Nicholas Li - MSFT