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
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 of Virtual Machine Bus

1. Run the Command Prompt as an administrator.

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

sc config vmbus start= demand

3. Close the command window and restart the computer.

The vmbus service is using the vmbus.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 8 installation media.