Cannot connect to Windows network? Event 4321

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