Host VBS Mode is automatically enabled whenever Workstation Pro is launched on a suitably capable Windows 10 (or later) host with Hyper-V enabled.
If Hyper-V is deactivated,
Workstation Pro operates in its traditional mode. And if Hyper-V is enabled, but the WHP feature is not sufficiently recent or not installed,
Workstation Pro fails to start.
Note: WHP is not supported on the Windows Server editions. Therefore,
Workstation Pro host VBS mode is not available on these editions.