I can reproduce an error when trying to join a 2003 or 2008 AD Domain. It states it cannot find a domain controller to connect to, yet it resolves the DNS name to its IP and the other way around. I found that your network connections install and select both IPv4 and IPv6. Without an IPv6 server handling those requests AD lookups fail. Uncheck IPv6 and try again and everything works fine.Mark

Mark - Interesting... My Win 2000 AD domain here has no problems with IPv6 - it ignores them completely. There IS one thing that may be different and may have something that could help. The only thing I had to do to get it working was to go into Windows 7's networking configuration and set the DNS to point to the server and from that point on, Windows 7 was able to find the domain controller and join it very quickly without any hassles. The Windows 2000 box runs the standard File/printer sharing feature, AD and has the DNS server running.

I am running a 2008 domain in native mode which uses ipv4 and ipv6 respectively. I have a dozen or so Vista/XP/2K3 vm's running and they all can join the domain no problem. When I build a beta or RC1 build it gets dhcp from my 2k8 DC which defines te proper dns server for the domain. I can browse and ping by name, however when I try to join the domain it comes up with a screen I've seen many times which are indicative of not finding a dns server to define where the DC is. As soon as I go to my NIC settings and deselect IPv6 and save, then go to a cmd prompt and do a ipconfig /flushdns and an ipconfig /registerdns and finally a nbtstat _R I can then join the 2k8 domain with no issues. I'm so used to it I do it as soon as the build completes.MarkMark

I always disable (unbind) ipv6, since none of my equipment supports it anyway.To unbind it, simply uncheck the checkbox on the property page for the NIC.

Unchecking the entry in the NIC properties does not disable IPv6 and may cause problems. You need to create a registry entry to disable IPv6. Disabling IPv6 may alleviate a symptom but it won't fix the underlying network problem. If something is not working with IPv6 installed there is a networking problem somewhere on the network. It could be a switch, a router, a server, or the workstation.http://support.microsoft.com/kb/929852Note that some features in Windows 7 require IPv6. Homegroup (not used in a domain setting) and Direct Access are two. Exchange 2007 (at least on the server) may require IPv6.http://support.microsoft.com/kb/952842What all this means is that disabling IPv6 is a stopgap method to work around an immediate problem. Going forward we will all have to learn how to deal with IPv6. If it is causing a problem now the best solution is to find and fixthe problem rather than alleviating a symptom caused by the problem.Kerry Brown MS-MVP - Windows Desktop Experience

Thanks for the info, Kerry.I didn't have a problem with IPv6, my routers don't support it and I'm not sure if my ISP does yet either.I unbound it because I wasn't really prepared to play with it yet.

Thank you also, derosec!