How to Transfer Virtual Machine from One Hard Disk to Another (External) Hard Disk
In this example, we are going to move the Windows Server 2012 64-bit virtual machine (VirtualBox) that is stored in “C:” drive to another hard disk (external or on the local network).
Go to default location where VirtualBox save “.vbox”. The default location is “C:\..\VirtualBox VMs”.
Move (cut and paste) the whole folder to another hard disk (external or on the local network).
Then in VirtualBox, go to “Tools”, and click “Add”.
Locate the folder that you just moved. Select the file that has the extension “.vbox”.
Click “Start”, VirtualBox is running a Windows Server 2012 64-bit virtual machine that is on another hard disk.