When you change the guest operating system type in the virtual machine settings, you change the setting for the guest operating system in the configuration file of the virtual machine. To change the guest operating system itself, you must install the new operating system in the virtual machine.

When you set the guest operating system type for a new virtual machine, vCenter Server applies configuration defaults based on the type of guest operating system. Changing the guest operating system type setting affects the available ranges and recommendations of the virtual machine settings.


Power off the virtual machine.


  1. In the VMware Host Client inventory, right-click the virtual machine and select Edit Settings.
  2. Click the VM Options tab and expand General Options.
  3. Select a guest operating system type and version.
    If you choose a Windows OS version that supports VBS and if the virtual machine's compatibility is ESXi 6.7 and later, the VBS row appears on the VM Options tab.
  4. (Optional) Click the Enable Virtualization Based Security to enable VBS.
    Important: Enabling VBS requires that you use EFI to boot the virtual machine. Changing the firmware might make the guest OS unbootable.
  5. Click Save to apply your changes.


The virtual machine configuration parameters for the guest operating system are changed. You can now install the guest operating system.