Receiving Event 4321: NetBT
The name “<workgroup name>:1d” could not be registered on the Interface with IP address <client’s IP address>. The machine with the IP address <another computer’s IP> did not allow the name to be claimed by this machine.

Solution 1

1 ) Turn off all devices on network
2 ) Unplug router
3 ) optional: turn off modem (cable, DSL, etc.)
4 ) count to 60 then turn back on modem
5 ) plug back in router
6 ) Turn back on computers
7 ) Check for 4321 error and windows network connectivity

Solution 1a

1 ) Check firewall
2 ) Firewall of pc <another computer’s IP> can be blocking requests from <client’s IP address>
3 ) Add internal network range (ex: 192.168.1.1 -> 192.168.1.255) to Trusted (or similar zone)
4 ) Also, make sure NetBIOS is not disabled or blocked by your firewall
4a ) If “NetBIOS” is not listed as an option, try allowing/enabling the following ports:
TCP 2869
UDP 1900

Solution 2

1 ) Change names of all computers and possibly the workgroup name too
2 ) Turn off all computers after name change
3 ) Turn back on, one at a time
4 ) Check for error and connectivity after each computer is on

Solution 3

Note: This could screw up your network shares. I will explain more at end (skip there first if you are unsure)
Note2: Designed For Windows XP

1 ) Goto Network Connections from Control Panel
2 ) Choose Properties From Your Network Connection

3 ) Select “Internet Protocol (TCP/IP)” then press Properties
4 ) In the “General” tab, press Advanced
5 ) Goto The “WINS” tab and choose “Disable NetBIOS over TCP/IP”

6 ) Press OK, and Again and again until you are out
7 ) Restart Computer
8 ) Repeat on other computers on network

Note: Instead of being able to access a computer by its name (ex. //home1) you now must access its IP (ex. //192.168.1.2), in which case I recommend using a static IP for your computers, see post below.

Hope that helps!
-James Hartig

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