Problem: EventID 4321

Event Viewer shows a system error at logon: 'The name "OFFICE:1d" could not be registered in the Interface with ID address 10.1.1.3. The machine with IP address 10.1.1.7 [another computer on the network] did not allow the name to be claimed by this machine'. Source: NetBT; EventID 4321. BUT "OFFICE" is the name of the workgroup, not the machine. AND the computer gets the IP address 10.1.1.3 anyway. There seems to be no problem once things get going. Should I leave well-enough alone, or can this be fixed?

While I don't understand the error message very well... if the only problem IS that error displayed in Event Viewer, then I wouldn't worry about it.

There is a computer with the same netbios name on the network as what you just setup. Go to Control Panel -> System -> Computer Name tab, click > Change button & change the computer name.

Description:
The name "Computer name" could not be registered on the Interface with IP address x.x.x.x. The machine with the IP address y.y.y.y did not allow the name to be claimed by this machine.

Causes and resolutions:

1. Two networking devices may have the same NetBIOS name. Or it may be caused by a NetBIOS name conflict between a workgroup and a domain/workgroup with the same NetBIOS name in the LAN.
   
   
2. If you have WINS server may sure you have correct WINS settings in the server and client.
   
   
3. You may need to clean the WINS records.
   
   
4. If this is multihomed computer, make both NICs are in the different subnet.
   
   
5. If this is the RRAS server, make sure only the one IP registers the record in the WINS.
   
   
6. Make sure the computer is in the correct subnet.

Since you say there appears to be no actual operational problem, just leave things as they are for the time being. The message could be the result of a transient glitch during initialization that gets sorted out. If things do start to go
awry, then investigate further because you should this will probably give you further diagnostic clues.