MBB Network Adapter Class Extension (MbbCx) Service Defaults in Windows 11
Default Settings
| Startup type: | Manual |
| Display name: | MBB Network Adapter Class Extension |
| Service name: | MbbCx |
| Service type: | kernel |
| Error control: | normal |
| Path: | %SystemRoot%\system32\drivers\MbbCx.sys |
| Registry key: | HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MbbCx |
Default Behavior
MBB Network Adapter Class Extension is a kernel driver. In Windows 11 it starts only if the user, an application or another service starts it. If MBB Network Adapter Class Extension fails to start, the failure details will be recorded into Event Log. Then Windows 11 should boot up and notify the user about the MbbCx service startup failure.
Dependencies
MBB Network Adapter Class Extension cannot be started, if the Network Adapter WDF Class Extension Library service won't start.
Restore Default Startup Configuration of MBB Network Adapter Class Extension
Before you begin doing this, make sure that all the services on which MBB Network Adapter Class Extension depends are configured by default and function properly. See the list of dependencies above.1. Run the Command Prompt as an administrator.
2. Copy the command below, paste it into the command window and press ENTER:
sc config MbbCx start= demand
3. Close the command window and restart the computer.
The MbbCx service is using the MbbCx.sys file that is located in the C:\Windows\system32\drivers directory. If the file is removed or corrupted, read this article to restore its original version from Windows 11 installation media.