I have a server that serves for Active Directory and DNS. Yesterday the following error occurred on the client side. DNS is not responding. Tried with multiple client computers and the issues continues. Nothing in the event viewer to indicate that DNS is having any issues. If the server is at the control alt delete screen then DNS starts working, however, if I am logged into the server, then DNS no longer works. This has me baffled. Any ideas?Tina Jansen

Hiya, 1: Do a virus/malware scan 2: have a look at the Start folder and Start registry How to Remove Startup Programs http://oreilly.com/windows/archive/how-to-remove-startup-programs.html Sounds like something starts up and runs when a user logs on.

I suggest you check DNS related issues with the help of command dcdiag/test:DNS and also use below link to know more about dcdiag. http://technet.microsoft.com/en-us/library/cc731968(WS.10).aspx Moreover next time onwards, seek DNS related queries in concerning forum"Network Infrastructure Servers":http://social.technet.microsoft.com/Forums/en-US/winserverNIS/threads Thank you for understanding. Regards, Ravikumar P

Hi, Agree with that some program running when user logs on caused the problem. You can start the computer in safe mode or perform a clean boot to check if problem disappears when using a minimal set of drivers and startup programs. Regards, Cicely

Nothing unusual in the start program. No viruses or rootkits. Issue persists.Tina Jansen

Hello, I assume that this is the only DC you have. In this case, proceed like the following: Make sure that this DC has one IP address in use and only one NIC card enabled: Multihoming a DC is not recommended: http://blogs.dirteam.com/blogs/acefekay/archive/2009/08/03/multihomed-dcs-with-dns-rras-and-or-pppoe-adapters.aspxConfigure the public DNS servers as forwarders and not in IP settings of the DCMake your DC point to its private IP address as primary DNS server and 127.0.0.1 as secondary one Once done, run ipconfig /registerdns and reboot your DC. For client computers, make them point to your DC as primary DNS server. Once done, try to flush the DNS cache on one of them using ipconfig /flushdns and check again. Of course, check that there is no filtering on port 53: You may need to disable temporary security software on the server and the client to troubleshoot. This posting is provided "AS IS" with no warranties or guarantees , and confers no rights.