When you type the Ipconfig /all command, the node type is displayed as unknown.
This behavior is symptomatic of an invalid data value in the EnableProxy Value Name, a REG_DWORD data type, at HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Netbt\Parameters.
To fix this problem, set the data value to 0 or 1. If the data value is set to 1 (True), the system will act as a proxy name server for the networks that NBT is bound to. A proxy name server answers broadcast queries for names that it has resolved through WINS. A proxy name server allows a network of Bnode implementations to connect to servers on other subnets that are registered with WINS.