Hi, I have a Windows 7 Pro SP1 workstation that hangs intermittently on startup before logon screen, perhaps once a week. The workstation is shut down every night. Whenever this happens, the following event is logged in the system log: Event source NetBT, ID 4321: The name <domain name> :1d could not be registered on the Interface with IP address <workstation IP-address>. The machine with the IP address <IP-address of a domain controller> did not allow the name to be claimed by this machine. On the DC that handles the request, nothing is logged. What to do?

Sounds like you have a duplicate netbios name on the network (another machine with the same 'computername'), or you have a service or application that is trying to register on the network with the same netbios name as the domain controller or domain name.

I forgot to mention that this has happened sporadically on other computers as well, so I don't think there is a naming conflict.

Hi, Please reference the links below: http://www.microsoft.com/technet/support/ee/transform.aspx?ProdName=Windows+Operating+System&ProdVer=5.2&EvtID=4321&EvtSrc=NetBT http://social.technet.microsoft.com/Forums/en/winservergen/thread/c0b8173b-5875-4eae-a09e-7df7cae61724 Best Regards, Kim ZhouPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi, Please reference the links below: http://www.microsoft.com/technet/support/ee/transform.aspx?ProdName=Windows+Operating+System&ProdVer=5.2&EvtID=4321&EvtSrc=NetBT http://social.technet.microsoft.com/Forums/en/winservergen/thread/c0b8173b-5875-4eae-a09e-7df7cae61724 Best Regards, Kim ZhouPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.