License Key for Virtual Machine

Question

I would like to know whether either of these are possible:

• When creating a VirtualBox VM with Windows 11, on a licensed Windows 11 host, can I use the hosts' key to register the new Windows 11 installation in the VM? I expect the answer is no because this would be considered two machines.
• Same VM, but can I use a key from an old Windows 10 machine which is basically dying (and the reason I want this new VM, to replace it)? I can unregister the Windows 10 machine, it still works sufficiently to do the slmgr /upk command on it.

Answer 1

Well, I tried it. Didn't work. Got the key from the old Win 10 Pro machine, ran the slmgr /upk command to deregister the key from that machine (successful response). Then tried using the key to activate the Win 11 virtual machine. Failed. It told me I can't use that key to activate.

Do I feel bad leaving it in an unactivated state? No. I've got a key, they just don't want to accept it. I paid for it already. Not paying again for another key when I've got one that's not associated with any machine and should be valid.