I am running VirtualBox v5.2.32 on an Ubuntu 18.04 host. I have created a Windows 10 (64-bit) guest. I installed VirtualBox v6.0.10 in the Windows 10 guest (Windows 10 Pro - v1903 - 64-bit). I am trying to create an Ubuntu (64-bit) guest inside the Windows 10 guest. I only see 32-bit options inside the Windows guest. After several attempts to resolve this, I am still only seeing 32-bit options.
The purpose for creating a VM inside a VM is to be able to ensure that VirtualBox is working so that I can test Vagrant configuration inside a Windows 10 environment. Our Vagrant config is using 64-bit base images, so I need to be able set up 64-bit guests inside this Windows 10 guest.
What I Have Already Tried
...on the Ubuntu Host
I have checked
Enable VT-x/AMD-V on the System > Acceleration tab in the Ubuntu host's VirtualBox config for the Windows 10 guest machine.
...on the Windows Guest
In the Windows guest machine, I can see that the host's physical CPU details are passed through in Settings > System > About and it shows as a "64-bit operating system, x64-based processor".
This is a vanilla Windows 10 Pro installation, no additional software (i.e., no addon virus protection software).
I inspected Windows Features to ensure that the following are not checked:
- Guarded Host
- Hyper V
- Virtual Machine Platform
- windows Hypervisor Platform
- Windows Subsystem for Linux
...because my googleing seems to indicate that some or all of these might be an issue.
Based on a VirtualBox forum (I have a 64bit host, but can't install 64bit guests), using
gpedit.msc, I set Local Computer Policy > Computer Configuration > Administrative Templates > System > Device Guard > Turn on Virtualization Based Security to
Disabled. I also check that Windows Security > Device Security > Core Isolation Details is set to
I have "repaired" the VirtualBox installation. I have uninstalled VirtualBox, rebooted, reinstalled, and then rebooted again.
Related Stack Exchange Questions and Other References
I looked at these related, previously asked questions and followed their suggestions as indicated in the steps above. Everything I am finding seems to be related to a Windows 64-bit host running directly on the host machine, not dealing with a Windows host which is itself a guest VM.
- Why does virtualbox only have 32-bit option, no 64-bit option on Windows 7?
- VirtualBox only allowing 32 bit OS
- Windows 10 (64 bit) is only showing 32 bit options and not 64 bit options
- Why is VirtualBox only showing 32-bit guest versions on my 64-bit host OS?
- VirtualBox only showing 32-bit and no 64-bit versions (easy fix)