I am trying to learn about VM's and thought I would start messing around with them to learn. I activated Windows 10 on a VM I created. If I delete this VM and create a new one can I use the same key again? Do I need to deactivate the key before deleting? Windows 10 was installed with a product key
Make sure you add a Microsoft account to the virtual machine, this way the activated key gets associated to the Microsoft account and then you if you create another virtual machine replacing the old one, just use the same MSA.
As far I understand (someone correct me if I'm wrong) there are two ways W10 logs activated keys:
1) Your Microsoft account
2) It generates a unique identifier for your hardware and is store in the cloud against your windows key.