OEM licenses generally cannot be transferred to another computer, or to a virtual machine. Most pre-installed versions of Windows have OEM licenses. The type of license you have for your Windows operating system can affect how you activate Windows after you start to use it in a Fusion virtual machine. If you import a virtual machine from another source, if you run the Boot Camp partition as a virtual machine, or if you migrate a physical PC to a virtual machine, Windows recognizes that the virtual hardware is different.

If you install Windows as a guest operating system in a new virtual machine, it requires activation the same as if you had installed it on a physical computer. If the hardware has changed, the Windows operating system requires reactivation.

When the Windows operating system starts up, it checks to see if it is running on the same hardware on which it was originally installed. You activate Windows either over the Internet or by phone with Microsoft Support. When you install Windows on a computer, you must activate it to use it.