In this article, I will explain how to enable Nested VT-X/AMD-V in Virtualbox. Last night when I was trying to bring up a VM using vagrant in my Ubuntu system which is actually running on Oracle VirtualBox, I was facing Stderr: VBoxManage: error: VT-x is not available (VERR_VMX_NO_VMX) error. When I further checked, I found that an option called Enable Nested VT-X/AMD-V under System->Processor is greyed out and hence causing this error. So before solving this error I thought to write an article about this so that it will help you guys as well in case you are also facing the same error.

How to Enable Nested VT-X/AMD-V in Virtualbox

Also Read: How to Display Nth Column of a File or an output using Windows Command Line

Step 1: Open CMD

In the first step, you need to open Windows Command line terminal by typing CMD on the bottom Search area. Once it shows up, right click on it and select Run as Administrator.

This will open the command line terminal in the administrator mode as shown below.

Step 2: Go to Installation Folder

In the next step, you need to go to VirtualBox folder using cd "Program Files\Oracle\VirtualBox" command as shown below. This folder contains all the VirtualBox executables components along with other important files in which we need to use VBoxManage. You can check about other components on Oracle VirtualBox Documentation.

C:\>cd "Program Files\Oracle\VirtualBox"

Step 3: Enable Nested VT-x/AMD-v

To enable the Nested VT-x/AMD-v in VirtualBox, you need to run VBoxManage modifyvm <vm_name> --nested-hw-virt on syntax. Since here I am enabling it for one of my VM called Ubuntu so I will use VBoxManage modifyvm Ubuntu --nested-hw-virt on command for this as you can see below.

C:\Program Files\Oracle\VirtualBox>VBoxManage modifyvm Ubuntu --nested-hw-virt on

Step 4: Verify Processor Setting

Finally we have to verify the changes by going to the affected VM System settings in the VirtualBox and see if tick mark on Enable Nested VT-x/AMD-v appears as expected. If it does then it should look like below. That's it !! You are now all set to proceed with your work.