The 1 in PhysicalDrive1 represents the Disk letter 1 that we discovered in the Step 2.vmdk The VMDK (Virtual Machine Disk) is a hard disk container file format for storing hard disk images used in Virtualization programs. You can use any other location for storing the Hard disk file. The C:\usb.vmdk is the path of our hard disk file.VBoxManage internalcommands createrawvmdk –filename C:\usb.vmdk -rawdisk \\.\PhysicalDrive1 Step 5: Now, we are going to create a bootable virtual hard disk. This will take you to the C:\Program Files\Oracle\VirtualBox directory. Step 4: In the Command Prompt window, type the following command, and then press the Enter key. Click on the Command Prompt (Admin) option to open Command Prompt with Administrative privileges. Step 3: Press the Windows + X keys together to open the Windows Power User Menu. Note the disk number of your USB drive that you want to boot in VirtualBox in this case, Disk 1 is the bootable USB drive. Disk 0 is the main computer disk, the disk that has the currently running Windows installed. Step 2: In the Disk Management window, you’ll see all of your disks and partitions. Type discmgmt.msc and press the OK button to open the Disk Management program in Windows. Step 1: Press the Windows + R key together to open the Run dialog box. Boot from a USB Drive in VirtualBox in Windows