Virtual Machine Bus (vmbus) Service Defaults in Windows 8

Microsoft Hyper-V Virtual Machine Bus Child Driver by Microsoft Corporation.

Default Settings

Startup type:Manual
Display name:Virtual Machine Bus
Service name:vmbus
Service type:kernel
Error control:normal
Group:System Bus Extender
Path:%SystemRoot%\System32\drivers\vmbus.sys
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\vmbus

Default Behavior

The Virtual Machine Bus service is a kernel device driver. In Windows 8 it will not be started until the user starts it. If Virtual Machine Bus fails to start, the error details are added to Windows 8 error log. When the operating system startup is complete, the user is being notified that the vmbus service hasn't been started.

Restore Default Startup Configuration for Virtual Machine Bus

1. Select your Windows 8 edition and update pack, and then click Download.

2. Save the Win8_vmbus_Service_Startup.cmd file to a local storage device.

3. Run the saved file as an administrator.

4. Restart the computer.

The vmbus service is using the vmbus.sys file that is located in the %WinDir%\System32\drivers folder. If the file is corrupted or deleted, you can put it back in there.