TCP/IP NetBIOS Helper (LmHosts) Service Defaults in Windows XP

Enables support for NetBIOS over TCP/IP (NetBT) service and NetBIOS name resolution.

Default Settings

Startup type: Automatic
Display name:TCP/IP NetBIOS Helper
Service name:LmHosts
Service type:share
Error control:normal
Object:NT AUTHORITY\LocalService
Path:%SystemRoot%\system32\svchost.exe -k LocalService
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LmHosts

Default Behavior

TCP/IP NetBIOS Helper is a Win32 service. In Windows XP it is starting automatically along with the operating system. Then the TCP/IP NetBIOS Helper service is running as NT AUTHORITY\LocalService in a shared process of svchost.exe. Other services and drivers are allowed to run in the same process. If the TCP/IP NetBIOS Helper fails to start, the technical information about the error is added to the Event Log. Windows XP startup should proceed, but a message box should be displayed informing the user that the LmHosts service has failed to start.


TCP/IP NetBIOS Helper depends on the following system components:

Restore Default Startup Configuration of TCP/IP NetBIOS Helper

Before you begin doing this, make sure that all the services on which TCP/IP NetBIOS Helper depends are configured by default and function properly. See the list of dependencies above.

1. Run the Command Prompt.

2. Copy the commands below, paste them into the command window and press ENTER:

sc config LmHosts start= auto
sc start LmHosts

3. Close the command window and restart the computer.

The LmHosts service is using the lmhsvc.dll file that is located in the C:\Windows\System32 directory. If the file is removed or corrupted, read this article to restore its original version from Windows XP installation media.