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.
I was able to install everything fine on my Mac, but when I was on Windows 10 VirtualBox was only showing and allowing me to install 32-bit versions of Linux. I figured out the fix - go into BiOS at startup and make sure the Intel Virtualization Tech is enabled. I had already checked HyperV was disabled in Windows Features. After enabling that BiOS setting I was able to successfully install. Go to the system configuration tab. You will find visualization technology as disabled. Turn it Enabled. Select virtualization technology row and press enter. Press F10 to save the changes and exit. Now I am able to select ubuntu 64 bit when I create VirtualBox.
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.
…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.
Oracle Virtualbox 32 Bit Only Download
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 Off.
I have 'repaired' the VirtualBox installation. I have uninstalled VirtualBox, rebooted, reinstalled, and then rebooted again.
Oracle Virtualbox Only 32 Bit Windows 10
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.