I copied the whole folder from "VirtualBox VMs" of Computer A and then migrated it to another Computer B. Later, I open the .vbox file from virtualbox of computer B. Everything works fine except that one of my obsolete yet licensed program detected significant hardware changes. It meant that I might need to play a substantial amount of so-called administrative cost to renew the licence. My question is why there is significant hardware changes. All the hardware id, mac address and harddisk ids are the same.