However, it's not inconceivable that I might delete the VM, or even
format the hard drive. In that event, what precautions can I
preemptively take?
I can only comment about VMWare, not too sure about VirtualBox. Also I am not a legal expert. Use your discretion if you want to try out the following. While Retail key has transfer rights, OEM or upgrade does not.
- Create a Virtual Windows 10 machine in your VMWare.
- Install Windows 10 in it and activate it using your key.
- If you have unused Windows 7 retail license, you can even install Windows 7 first, then activate it and then upgrade your Windows 7 to Windows 10. Even though the free upgrade window is over long back, it still works and you will hopefully get a Windows 10 digital license.
- Eventually regardless if you upgraded from Windows 7/8.1 or got your Windows 10 activated using your key, you will have a Digital License whereby the hardware fingerprint will be stored on Microsoft Activation Servers. As a result you do not need to enter the key again on the same hardware even when you do a clean install of matching edition of Windows 10 on it.
Access .VMX file that holds the Virtual Hardware parameters for your Windows 10 and note down the following two lines. You can right click on the file and open the file in any plain text editor. You must not lose these two lines. That's sort of your Virtual Motherboard. So copy them exactly as they are in a separate document, preferably a plain text file and keep it safe.
uuid.bios = xxxxxxxxxxxxxxx
uuid.location = xxxxxxxxxxxxx
Go ahead and delete the VM whenever you wish.
- Create a new VM, preferably on the same Host Machine as earlier. A new .VMX file will be created.
- Do not attach any CD/DVD/ISO/Bootable pen drive to it and just run it once. It will boot to nothing. Shut it down. This first run creates UUID in the .VMX.
- Open .VMX and replace the
uuid.bios
and uuid.location
entries with what you copied from earlier VM. Update them exactly as they were, in this new .VMX.
- Save .VMX and run the VM, again without any CD/DVD/ISO/Bootable pen drive etc
- VMWare will prompt you something like,
'Did you copy or move the Virtual Machine?'
(This is because VMWare records the hash of certain parameters from .VMX including the path where it is located, change in UUID or change in path = You either copied or moved the machine)
- Select
'I Moved it'
option.
- Now VMWare will allocate or rather keep the same UUID that you updated before in the .VMX file and configure the VM.
- Close the VM, attach your Windows 10 bootable device, go ahead and install the matching edition of your Windows 10 for which you had a Digital License earlier on VM. Select 'I don't have a product key' option during install and proceed.
- Windows 10 in that new VM will get automatically activated when you connect your VM to the Internet as the hardware fingerprint will match.
Option 2
After you install and activate Virtual Windows 10, shut it down and take a copy of the entire folder where it resides elsewhere, may be a backup hard drive/SSD/Pen drive or so. However you might need at least 40 - 50 GB of free space as your virtual disks might hold that much of volume.
Delete the original VM. Now replace it with the copy such that the original path must match. If original folder was D:\VM\My-Windows-10
then you must move it to the same path.
Everything is now same as earlier. Your Windows 10 remains activated and back to the original state as you installed it first.
Note - Even though Moving and Copying is in principle possible due to virtualization environment and software, make sure that you never run the backup copy even if you have an option to choose 'I moved it
', then you are running two copies of your Windows 10 and that's a clear violation of licensing terms. 1 Key - 1 Machine.