от 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